diff --git a/lib/utils/1m.js b/lib/utils/1m.js
index 74236f92..6de18a90 100644
--- a/lib/utils/1m.js
+++ b/lib/utils/1m.js
@@ -406,10 +406,10 @@ function hasDuplicates(array) {
   return uniqueValues.size !== array.length;
 }
 
-const cellsInColumnUnique = (dh) => (shared_key_name, new_value = null) => {
+const cellsInColumnUnique = (dh) => (shared_key_name, filter_value = null) => {
   const columnIndex = dh.getColumnIndexByFieldName(shared_key_name);
   const columnValues = getNonEmptyColumnValues(dh.hot, columnIndex);
-  if (new_value) columnValues.push(new_value);
+  if (filter_value !== null) columnValues.filter(el => el === filter_value);
   return hasDuplicates(columnValues);
 }
 
@@ -552,16 +552,24 @@ const bindChangeEmitter = (appContext) => (dh) => {
               : ACTION.UPDATE;
 
             // TODO: modal continuation interface
-
-            const cellIsUnique = cellsInColumnUnique(dh)(key_name);
-            const willHaveDuplicateValues = cellsInColumnUnique(dh)(key_name, Object.values(row_changes[row].newValues)[0]);
-
-            // propagate deletion when it is the final key
+            const currentValue = row_changes[row].oldValues[column_index];
+            
+            // propagate deletion when the deleted cell was unique of its kind
             // always propagate updates
             const propagates = updateActionType === ACTION.DELETE ? 
-                !cellIsUnique
+                // if deletion is triggering, the current non empty column values should still be one down from the original value
+                // NOTE: if this is problematic, need to replace *all* handsontable with CRUD
+                getNonEmptyColumnValues(dh.hot, column_index).filter(el => el === currentValue).length === 0
               : true;
 
+            // console.warn(
+            //   updateActionType, 
+            //   currentValue,
+            //   futureValue, 
+            //   getNonEmptyColumnValues(dh.hot, column_index),
+            //   getNonEmptyColumnValues(dh.hot, column_index).filter(el => el === currentValue).length === 0, 
+            //   propagates);
+
             const details = {
               emitted_by: dh.class_assignment,
               target: dh.class_assignment,
@@ -579,15 +587,17 @@ const bindChangeEmitter = (appContext) => (dh) => {
               propagates
             };
 
-            // warn about deletion if it's the final key 
-            if (updateActionType === ACTION.DELETE && !cellIsUnique && propagates) {
-              console.warn("PROPAGATION:", "Row collections with key will be deleted", details);
-            }
+            if (propagates) {
+              // warn about deletion if it's the final key 
+              if (updateActionType === ACTION.DELETE) {
+                console.warn("PROPAGATION:", "Row collections with key will be deleted", details);
+              }
 
-            // // warn if update will cause a duplicate that merges entries in child tables which share that same key
-            // if (updateActionType === ACTION.UPDATE && willHaveDuplicateValues && propagates) {
-            //   console.warn("PROPAGATION:", "Row collections will merge with existing those of existing key value", details);
-            // }
+              // // warn if update will cause a duplicate that merges entries in child tables which share that same key
+              if (updateActionType === ACTION.UPDATE && getNonEmptyColumnValues(dh.hot, column_index).filter(el => el === currentValue).length + 1 > 1) {
+                console.warn("PROPAGATION:", "Row collections will merge with existing those of existing key value", details);
+              }
+            }
 
             dispatchHandsontableUpdate(updateActionType, details);
 
@@ -796,6 +806,7 @@ const handleAction = (appContext) => (dh) => (action, details) => {
           }
         };
       } else {
+        // propagation
         for (let col_index in shared_key_details.key_indexes) {
           updateRows(dh, [
             col_index,