diff --git a/src/computational_graph/optimize.jl b/src/computational_graph/optimize.jl
index eb856e78..206fe576 100644
--- a/src/computational_graph/optimize.jl
+++ b/src/computational_graph/optimize.jl
@@ -17,7 +17,6 @@ function optimize!(graphs::Union{Tuple,AbstractVector{<:AbstractGraph}}; verbose
     else
         graphs = collect(graphs)
         leaf_mapping = remove_duplicated_leaves!(graphs, verbose=verbose, normalize=normalize)
-        # merge_all_chains!(graphs, verbose=verbose)
         flatten_all_chains!(graphs, verbose=verbose)
         merge_all_linear_combinations!(graphs, verbose=verbose)
         return leaf_mapping
@@ -44,146 +43,10 @@ function optimize(graphs::Union{Tuple,AbstractVector{<:AbstractGraph}}; verbose=
     return graphs_new, leaf_mapping
 end
 
-"""
-    function merge_all_chain_prefactors!(g::AbstractGraph; verbose=0)
-
-    In-place merge prefactors of all nodes representing trivial unary chains towards the root level for a single graph.
-
-# Arguments:
-- `g`: An AbstractGraph.
-- `verbose`: Level of verbosity (default: 0).
-
-# Returns:
-- Optimized graph.
-# 
-"""
-function merge_all_chain_prefactors!(g::AbstractGraph; verbose=0)
-    verbose > 0 && println("merge prefactors of all nodes representing trivial unary chains toward root level.")
-    # Post-order DFS
-    for sub_g in g.subgraphs
-        merge_all_chain_prefactors!(sub_g)
-        merge_chain_prefactors!(sub_g)
-    end
-    merge_chain_prefactors!(g)
-    return g
-end
-
-"""
-    function merge_all_chain_prefactors!(graphs::AbstractVector{<:AbstractGraph}; verbose=0)
-
-    In-place merge prefactors of all nodes representing trivial unary chains towards the root level for given graphs.
-
-# Arguments:
-- `graphs`: An AbstractVector of graphs.
-- `verbose`: Level of verbosity (default: 0).
-
-# Returns:
-- Optimized graphs.
-# 
-"""
-function merge_all_chain_prefactors!(graphs::AbstractVector{<:AbstractGraph}; verbose=0)
-    verbose > 0 && println("merge prefactors of all nodes representing trivial unary chains toward root level.")
-    # Post-order DFS
-    for g in graphs
-        merge_all_chain_prefactors!(g.subgraphs)
-        merge_chain_prefactors!(g)
-    end
-    return graphs
-end
-
-"""
-    function merge_all_factorless_chains!(g::AbstractGraph; verbose=0)
-
-    In-place merge all nodes representing factorless trivial unary chains within a single graph.
-
-# Arguments:
-- `g`: An AbstractGraph.
-- `verbose`: Level of verbosity (default: 0).
-
-# Returns:
-- Optimized graph.
-# 
-"""
-function merge_all_factorless_chains!(g::AbstractGraph; verbose=0)
-    verbose > 0 && println("merge all nodes representing factorless trivial unary chains.")
-    # Post-order DFS
-    for sub_g in g.subgraphs
-        merge_all_factorless_chains!(sub_g)
-        merge_factorless_chain!(sub_g)
-    end
-    merge_factorless_chain!(g)
-    return g
-end
-
-"""
-    function merge_all_factorless_chains!(graphs::AbstractVector{<:AbstractGraph}; verbose=0)
-
-    In-place merge all nodes representing factorless trivial unary chains within given graphs.
-
-# Arguments:
-- `graphs`: An AbstractVector of graphs.
-- `verbose`: Level of verbosity (default: 0).
-
-# Returns:
-- Optimized graphs.
-# 
-"""
-function merge_all_factorless_chains!(graphs::AbstractVector{<:AbstractGraph}; verbose=0)
-    verbose > 0 && println("merge all nodes representing factorless trivial unary chains.")
-    # Post-order DFS
-    for g in graphs
-        merge_all_factorless_chains!(g.subgraphs)
-        merge_factorless_chain!(g)
-    end
-    return graphs
-end
-
-"""
-    function merge_all_chains!(g::AbstractGraph; verbose=0)
-
-    In-place merge all nodes representing trivial unary chains within a single graph.
-    This function consolidates both chain prefactors and factorless chains.
-
-# Arguments:
-- `g`: An AbstractGraph.
-- `verbose`: Level of verbosity (default: 0).
-
-# Returns:
-- Optimized graph.
-# 
-"""
-function merge_all_chains!(g::AbstractGraph; verbose=0)
-    verbose > 0 && println("merge all nodes representing trivial unary chains.")
-    merge_all_chain_prefactors!(g, verbose=verbose)
-    merge_all_factorless_chains!(g, verbose=verbose)
-    return g
-end
-
-"""
-    function merge_all_chains!(graphs::AbstractVector{<:AbstractGraph}; verbose=0) where {G<:AbstractGraph}
-
-    In-place merge all nodes representing trivial unary chains in given graphs. 
-    This function consolidates both chain prefactors and factorless chains.
-
-# Arguments:
-- `graphs`: An AbstractVector of graphs.
-- `verbose`: Level of verbosity (default: 0).
-
-# Returns:
-- Optimized graphs.
-# 
-"""
-function merge_all_chains!(graphs::AbstractVector{<:AbstractGraph}; verbose=0)
-    verbose > 0 && println("merge all nodes representing trivial unary chains.")
-    merge_all_chain_prefactors!(graphs, verbose=verbose)
-    merge_all_factorless_chains!(graphs, verbose=verbose)
-    return graphs
-end
-
 """
     function flatten_all_chains!(g::AbstractGraph; verbose=0)
-
-    In-place flattens all nodes representing trivial unary chains in the given graph `g`. 
+F
+    Flattens all nodes representing trivial unary chains in-place in the given graph `g`. 
 
 # Arguments:
 - `graphs`: The graph to be processed.
diff --git a/src/computational_graph/transform.jl b/src/computational_graph/transform.jl
index 7c291ca4..a0683380 100644
--- a/src/computational_graph/transform.jl
+++ b/src/computational_graph/transform.jl
@@ -157,134 +157,6 @@ function replace_subgraph(g::AbstractGraph, w::AbstractGraph, m::AbstractGraph)
     return g_new
 end
 
-"""
-    function merge_factorless_chain!(g::AbstractGraph)
-
-    Simplifies `g` in-place if it represents a factorless trivial unary chain. For example, +(+(+g)) ↦ g.
-
-    Does nothing unless g has the following structure: 𝓞 --- 𝓞' --- ⋯ --- 𝓞'' ⋯ (!),
-    where the stop-case (!) represents a leaf, a non-trivial unary operator 𝓞'''(g) != g,
-    a node with non-unity multiplicative prefactor, or a non-unary operation.
-
-# Arguments:
-- `g::AbstractGraph`: graph to be modified
-"""
-function merge_factorless_chain!(g::AbstractGraph)
-    if unary_istrivial(g.operator) && onechild(g) && isfactorless(g)
-        child = eldest(g)
-        for field in fieldnames(typeof(g))
-            value = getproperty(child, field)
-            setproperty!(g, field, value)
-        end
-    end
-    while unary_istrivial(g.operator) && onechild(g) && isfactorless(g)
-        child = eldest(g)
-        for field in fieldnames(typeof(g))
-            value = getproperty(child, field)
-            setproperty!(g, field, value)
-        end
-    end
-    return g
-end
-
-"""
-    function merge_factorless_chain(g::AbstractGraph)
-
-    Returns a simplified copy of `g` if it represents a factorless trivial unary chain.
-    Otherwise, returns the original graph. For example, +(+(+g)) ↦ g.
-
-    Does nothing unless g has the following structure: 𝓞 --- 𝓞' --- ⋯ --- 𝓞'' ⋯ (!),
-    where the stop-case (!) represents a leaf, a non-trivial unary operator 𝓞'''(g) != g,
-    a node with non-unity multiplicative prefactor, or a non-unary operation.
-
-# Arguments:
-- `g::AbstractGraph`: graph to be modified
-"""
-function merge_factorless_chain(g::AbstractGraph)
-    while unary_istrivial(g.operator) && onechild(g) && isfactorless(g)
-        g = eldest(g)
-    end
-    return g
-end
-
-"""
-    function merge_chain_prefactors!(g::AbstractGraph)
-
-    Simplifies subgraphs of g representing trivial unary chains by merging their 
-    subgraph factors toward root level, e.g., 2*(3*(5*g)) + 7*(9*(h)) ↦ 30*(*(*g)) + 63*(*h). 
-
-    Acts only on subgraphs of g with the following structure: 𝓞 --- 𝓞' --- ⋯ --- 𝓞'' ⋯ (!),
-    where the stop-case (!) represents a leaf, a non-trivial unary operator 𝓞'''(g) != g, or a non-unary operation.
-
-# Arguments:
-- `g::AbstractGraph`: graph to be modified
-"""
-function merge_chain_prefactors!(g::AbstractGraph)
-    for (i, child) in enumerate(g.subgraphs)
-        total_chain_factor = 1
-        while onechild(child)
-            # Break case: end of trivial unary chain
-            unary_istrivial(child.operator) == false && break
-            # Move this subfactor to running total
-            total_chain_factor *= child.subgraph_factors[1]
-            child.subgraph_factors[1] = 1
-            # Descend one level
-            child = eldest(child)
-        end
-        # Update g subfactor with total factors from children
-        g.subgraph_factors[i] *= total_chain_factor
-    end
-    return g
-end
-
-"""
-    function merge_chain_prefactors(g::AbstractGraph)
-
-    Returns a copy of g with subgraphs representing trivial unary chains simplified by merging 
-    their subgraph factors toward root level, e.g., 2*(3*(5*g)) + 7*(9*(h)) ↦ 30*(*(*g)) + 63*(*h).
-
-    Acts only on subgraphs of g with the following structure: 𝓞 --- 𝓞' --- ⋯ --- 𝓞'' ⋯ (!),
-    where the stop-case (!) represents a leaf, a non-trivial unary operator 𝓞'''(g) != g, or a non-unary operation.
-
-# Arguments:
-- `g::AbstractGraph`: graph to be modified
-"""
-merge_chain_prefactors(g::AbstractGraph) = merge_chain_prefactors!(deepcopy(g))
-
-"""
-    function merge_chains!(g::AbstractGraph)
-
-    Converts subgraphs of g representing trivial unary chains
-    to in-place form, e.g., 2*(3*(5*g)) + 7*(9*(h)) ↦ 30*g + 63*h.
-
-    Acts only on subgraphs of g with the following structure: 𝓞 --- 𝓞' --- ⋯ --- 𝓞'' ⋯ (!),
-    where the stop-case (!) represents a leaf, a non-trivial unary operator 𝓞'''(g) != g, or a non-unary operation.
-
-# Arguments:
-- `g::AbstractGraph`: graph to be modified
-"""
-function merge_chains!(g::AbstractGraph)
-    merge_chain_prefactors!(g)  # shift chain subgraph factors towards root level
-    for sub_g in g.subgraphs    # prune factorless chain subgraphs
-        merge_factorless_chain!(sub_g)
-    end
-    return g
-end
-
-"""
-    function merge_chains(g::AbstractGraph)
-
-    Returns a copy of a graph g with subgraphs representing trivial unary chain
-    simplified to in-place form, e.g., 2*(3*(5*g)) + 7*(9*(h)) ↦ 30*g + 63*h.
-
-    Acts only on subgraphs of g with the following structure: 𝓞 --- 𝓞' --- ⋯ --- 𝓞'' ⋯ (!),
-    where the stop-case (!) represents a leaf, a non-trivial unary operator 𝓞'''(g) != g, or a non-unary operation.
-
-# Arguments:
-- `g::AbstractGraph`: graph to be modified
-"""
-merge_chains(g::AbstractGraph) = merge_chains!(deepcopy(g))
-
 """
     function flatten_chains!(g::AbstractGraph)
 
diff --git a/test/computational_graph.jl b/test/computational_graph.jl
index e56643a3..37ab49bf 100644
--- a/test/computational_graph.jl
+++ b/test/computational_graph.jl
@@ -111,14 +111,8 @@ Graphs.unary_istrivial(::Type{O}) where {O<:Union{O1,O2,O3}} = true
             g4p = Graph([g3p,]; operator=Graphs.Sum())
             @test Graphs.unary_istrivial(Graphs.Prod)
             @test Graphs.unary_istrivial(Graphs.Sum)
-            @test Graphs.merge_factorless_chain(g2) == g1
-            @test Graphs.merge_factorless_chain(g3) == g1
-            @test Graphs.merge_factorless_chain(g4) == g1
-            @test Graphs.merge_factorless_chain(g3p) == g3p
-            @test Graphs.merge_factorless_chain(g4p) == g3p
             g5 = Graph([g1,]; operator=O())
             @test Graphs.unary_istrivial(O) == false
-            @test Graphs.merge_factorless_chain(g5) == g5
         end
         g1 = Graph([])
         g2 = Graph([g1,]; subgraph_factors=[5,], operator=Graphs.Prod())
@@ -130,43 +124,6 @@ Graphs.unary_istrivial(::Type{O}) where {O<:Union{O1,O2,O3}} = true
         g2p = Graph([g1, g2]; operator=Graphs.Sum())
         g3p = Graph([g2p,]; subgraph_factors=[3,], operator=Graphs.Prod())
         gp = Graph([g3p,]; subgraph_factors=[2,], operator=Graphs.Prod())
-        @testset "Merge chains" begin
-            # g ↦ 30*(*(*g1))
-            g_merged = Graphs.merge_chain_prefactors(g)
-            @test g_merged.subgraph_factors == [30,]
-            @test all(isfactorless(node) for node in PreOrderDFS(eldest(g_merged)))
-            # in-place form
-            gc = deepcopy(g)
-            Graphs.merge_chain_prefactors!(gc)
-            @test isequiv(gc, g_merged, :id)
-            # gp ↦ 6*(*(g1 + 5*g1))
-            gp_merged = Graphs.merge_chain_prefactors(gp)
-            @test gp_merged.subgraph_factors == [6,]
-            @test isfactorless(eldest(gp)) == false
-            @test isfactorless(eldest(gp_merged))
-            @test eldest(eldest(gp_merged)) == g2p
-            # g ↦ 30*g1
-            g_merged = merge_chains(g)
-            @test isequiv(g_merged, 30 * g1, :id)
-            # in-place form
-            merge_chains!(g)
-            @test isequiv(g, 30 * g1, :id)
-            # gp ↦ 6*(g1 + 5*g1)
-            gp_merged = merge_chains(gp)
-            @test isequiv(gp_merged, 6 * g2p, :id)
-            # Test a generic trivial unary chain
-            # *(O3(5 * O2(3 * O1(2 * h)))) ↦ 30 * h
-            h = Graph([])
-            h1 = Graph([h,]; subgraph_factors=[2,], operator=O1())
-            h2 = Graph([h1,]; subgraph_factors=[3,], operator=O2())
-            h3 = Graph([h2,]; subgraph_factors=[5,], operator=O3())
-            h4 = Graph([h3,]; operator=Graphs.Prod())
-            h4_merged = merge_chains(h4)
-            @test isequiv(h4_merged, 30 * h, :id)
-            # in-place form
-            merge_chains!(h4)
-            @test isequiv(h4, 30 * h, :id)
-        end
         @testset "Merge prefactors" begin
             g1 = propagator(𝑓⁺(1)𝑓⁻(2))
             h1 = FeynmanGraph([g1, g1], drop_topology(g1.properties); subgraph_factors=[1, 2], operator=Graphs.Sum())
@@ -239,40 +196,6 @@ Graphs.unary_istrivial(::Type{O}) where {O<:Union{O1,O2,O3}} = true
         end
     end
     @testset verbose = true "Optimizations" begin
-        @testset "Remove one-child parents" begin
-            # h = O(7 * (5 * (3 * (2 * g)))) ↦ O(210 * g)
-            g1 = Graph([])
-            g2 = 2 * g1
-            g3 = Graph([g2,]; subgraph_factors=[3,], operator=Graphs.Prod())
-            g4 = Graph([g3,]; subgraph_factors=[5,], operator=Graphs.Prod())
-            h = Graph([g4,]; subgraph_factors=[7,], operator=O())
-            hvec = repeat([deepcopy(h)], 3)
-            # Test on a single graph
-            Graphs.merge_all_chains!(h)
-            @test h.operator == O
-            @test h.subgraph_factors == [210,]
-            @test eldest(h) == g1
-            # Test on a vector of graphs
-            Graphs.merge_all_chains!(hvec)
-            @test all(h.operator == O for h in hvec)
-            @test all(h.subgraph_factors == [210,] for h in hvec)
-            @test all(eldest(h) == g1 for h in hvec)
-
-            g2 = 2 * g1
-            g3 = Graph([g2,]; subgraph_factors=[3,], operator=Graphs.Prod())
-            g4 = Graph([g3,]; subgraph_factors=[5,], operator=Graphs.Prod())
-            h0 = Graph([g1, g4]; subgraph_factors=[2, 7], operator=O())
-            Graphs.merge_all_chains!(h0)
-            @test h0.subgraph_factors == [2, 210]
-            @test h0.subgraphs[2] == g1
-
-            h1 = Graph([h0]; subgraph_factors=[3,], operator=Graphs.Prod())
-            h2 = Graph([h1]; subgraph_factors=[5,], operator=Graphs.Prod())
-            h = Graph([h2]; subgraph_factors=[7,], operator=O())
-            Graphs.merge_all_chains!(h)
-            @test h.subgraph_factors == [105]
-            @test eldest(h) == h0
-        end
         @testset "Flatten all chains" begin
             l0 = Graph([])
             l1 = Graph([l0]; subgraph_factors=[2])
@@ -298,14 +221,6 @@ Graphs.unary_istrivial(::Type{O}) where {O<:Union{O1,O2,O3}} = true
             @test isequiv(r3, Graph([g1, g1,]; subgraph_factors=[12, 210], operator=O()), :id)
             Graphs.flatten_all_chains!(rvec)
             @test rvec == [r1, r2, r3]
-
-            Graphs.merge_all_chains!(rvec1)
-            @test rvec1[1].subgraph_factors == [210]
-            @test eldest(rvec1[1]) == g1
-            @test rvec1[2].subgraph_factors == [-1]
-            @test eldest(rvec1[2]) == g1    #  BUG!
-            @test rvec1[3].subgraph_factors == [2, 7]
-            @test rvec1[3].subgraphs == [g1, g1]  #  BUG!
         end
         @testset "merge all linear combinations" begin
             g1 = Graph([])
@@ -540,14 +455,8 @@ end
             g4p = FeynmanGraph([g3p,], drop_topology(g3p.properties); operator=Graphs.Sum())
             @test Graphs.unary_istrivial(Graphs.Prod)
             @test Graphs.unary_istrivial(Graphs.Sum)
-            @test Graphs.merge_factorless_chain(g2) == g1
-            @test Graphs.merge_factorless_chain(g3) == g1
-            @test Graphs.merge_factorless_chain(g4) == g1
-            @test Graphs.merge_factorless_chain(g3p) == g3p
-            @test Graphs.merge_factorless_chain(g4p) == g3p
             g5 = FeynmanGraph([g1,], drop_topology(g1.properties); operator=O())
             @test Graphs.unary_istrivial(O) == false
-            @test Graphs.merge_factorless_chain(g5) == g5
         end
         g1 = propagator(𝑓⁻(1)𝑓⁺(2))
         g2 = FeynmanGraph([g1,], g1.properties; subgraph_factors=[5,], operator=Graphs.Prod())
@@ -559,43 +468,6 @@ end
         g2p = FeynmanGraph([g1, g2], drop_topology(g1.properties))
         g3p = FeynmanGraph([g2p,], g2p.properties; subgraph_factors=[3,], operator=Graphs.Prod())
         gp = FeynmanGraph([g3p,], g3p.properties; subgraph_factors=[2,], operator=Graphs.Prod())
-        @testset "Merge chains" begin
-            # g ↦ 30*(*(*g1))
-            g_merged = Graphs.merge_chain_prefactors(g)
-            @test g_merged.subgraph_factors == [30,]
-            @test all(isfactorless(node) for node in PreOrderDFS(eldest(g_merged)))
-            # in-place form
-            gc = deepcopy(g)
-            Graphs.merge_chain_prefactors!(gc)
-            @test isequiv(gc, g_merged, :id)
-            # gp ↦ 6*(*(g1 + 5*g1))
-            gp_merged = Graphs.merge_chain_prefactors(gp)
-            @test gp_merged.subgraph_factors == [6,]
-            @test isfactorless(eldest(gp)) == false
-            @test isfactorless(eldest(gp_merged))
-            @test isequiv(eldest(eldest(gp_merged)), g2p, :id)
-            # g ↦ 30*g1
-            g_merged = merge_chains(g)
-            @test isequiv(g_merged, 30 * g1, :id)
-            # in-place form
-            merge_chains!(g)
-            @test isequiv(g, 30 * g1, :id)
-            # gp ↦ 6*(g1 + 5*g1)
-            gp_merged = merge_chains(gp)
-            @test isequiv(gp_merged, 6 * g2p, :id)
-            # Test a generic trivial unary chain
-            # *(O3(5 * O2(3 * O1(2 * h)))) ↦ 30 * h
-            h = propagator(𝑓⁻(1)𝑓⁺(2))
-            h1 = FeynmanGraph([h,], h.properties; subgraph_factors=[2,], operator=O1())
-            h2 = FeynmanGraph([h1,], h1.properties; subgraph_factors=[3,], operator=O2())
-            h3 = FeynmanGraph([h2,], h2.properties; subgraph_factors=[5,], operator=O3())
-            h4 = FeynmanGraph([h3,], h3.properties; operator=Graphs.Prod())
-            h4_merged = merge_chains(h4)
-            @test isequiv(h4_merged, 30 * h, :id)
-            # in-place form
-            merge_chains!(h4)
-            @test isequiv(h4, 30 * h, :id)
-        end
         @testset "Merge prefactors" begin
             g1 = propagator(𝑓⁺(1)𝑓⁻(2))
             h1 = FeynmanGraph([g1, g1], drop_topology(g1.properties), subgraph_factors=[1, 2])
@@ -630,32 +502,6 @@ end
     end
 
     @testset verbose = true "Optimizations" begin
-        @testset "Remove one-child parents" begin
-            g1 = propagator(𝑓⁻(1)𝑓⁺(2))
-            g2 = 2 * g1
-            # h = O(7 * (5 * (3 * (2 * g)))) ↦ O(210 * g)
-            g3 = FeynmanGraph([g2,], g2.properties; subgraph_factors=[3,], operator=Graphs.Prod())
-            g4 = FeynmanGraph([g3,], g3.properties; subgraph_factors=[5,], operator=Graphs.Prod())
-            h = FeynmanGraph([g4,], drop_topology(g4.properties); subgraph_factors=[7,], operator=O())
-            hvec = repeat([h], 3)
-            # Test on a single graph
-            Graphs.merge_all_chains!(h)
-            @test h.operator == O
-            @test h.subgraph_factors == [210,]
-            @test isequiv(eldest(h), g1, :id)
-            # Test on a vector of graphs
-            Graphs.merge_all_chains!(hvec)
-            @test all(h.operator == O for h in hvec)
-            @test all(h.subgraph_factors == [210,] for h in hvec)
-            @test all(isequiv(eldest(h), g1, :id) for h in hvec)
-
-            g2 = 2 * g1
-            g3 = FeynmanGraph([g2,], g2.properties; subgraph_factors=[3,], operator=Graphs.Prod())
-            g4 = FeynmanGraph([g3,], g3.properties; subgraph_factors=[5,], operator=Graphs.Prod())
-            h = FeynmanGraph([g1, g4], drop_topology(g4.properties); subgraph_factors=[2, 7], operator=O())
-            Graphs.merge_all_chains!(h)
-            @test h.subgraph_factors == [2, 210]
-        end
         @testset "optimize" begin
             g1 = propagator(𝑓⁻(1)𝑓⁺(2))
             g2 = 2 * g1