diff --git a/Overlaps.cpp b/Overlaps.cpp
index 3e60236..ad96ceb 100644
--- a/Overlaps.cpp
+++ b/Overlaps.cpp
@@ -3101,10 +3101,7 @@ typedef struct {
     long long n_read;
     uint64_t *readLen;
     ma_sub_t *coverage_cut;
-    int *counter;   // per thread counter
-    uint32_t **buf_u32_q;    // per thread linear buffers
-    uint32_t **buf_u32_t; 
-    int* buf_u32_n; int* buf_u32_m;
+    int counter;  // NOTE this might RACE during update, but it's an output and not used elsewhere
 }hitcontain_aux_t;
 
 static void hamt_hit_contained_drop_singleton_worker(void *data, long i_r, int tid){  // callback for kt_for()
@@ -3425,15 +3422,15 @@ static void hamt_hit_contained_drop_singleton_worker_v2(void *data, long i_r, in
                                 __func__, (int)Get_NAME_LENGTH(R_INF, w), Get_NAME(R_INF, w));
                 }    
                 need_to_protect = 0;
-                // note: do not go to finish yet, we still need to check other neighbors and see if any of them ask for protection.
-            }else{
-                if (verbose>1){
-                    fprintf(stderr, "[debug::%s]     ~ neighbor %.*s hinted more haps\n",
-                                __func__, (int)Get_NAME_LENGTH(R_INF, w), Get_NAME(R_INF, w));
-                }
-                need_to_protect = 1;
                 goto finish;
             }
+
+            if (verbose>1){
+                fprintf(stderr, "[debug::%s]     ~ neighbor %.*s hinted more haps\n",
+                            __func__, (int)Get_NAME_LENGTH(R_INF, w), Get_NAME(R_INF, w));
+            }
+            need_to_protect = 1;
+            goto finish;
         }else{
             if (verbose>1){
                 fprintf(stderr, "[debug::%s]     ~ neighbor %.*s ok\n",
@@ -3457,17 +3454,10 @@ static void hamt_hit_contained_drop_singleton_worker_v2(void *data, long i_r, in
                             (int)Get_NAME_LENGTH(R_INF, hits[i]->tn), Get_NAME(R_INF, hits[i]->tn));
             }
         }
-        d->counter[tid]++;
-        for (i=0; i<buf_len; i++){ 
-            // delete_single_edge_both_dir(sources, coverage_cut, (uint32_t)i_r, hits[i]->tn);
-            if (d->buf_u32_n[tid]>=d->buf_u32_m[tid]){
-                d->buf_u32_m[tid] = d->buf_u32_m[tid] + (d->buf_u32_m[tid]>>1);
-                d->buf_u32_q[tid] = (uint32_t*)realloc(d->buf_u32_q[tid], sizeof(uint32_t)*d->buf_u32_m[tid]);
-                d->buf_u32_t[tid] = (uint32_t*)realloc(d->buf_u32_t[tid], sizeof(uint32_t)*d->buf_u32_m[tid]);
-            }
-            d->buf_u32_q[tid][d->buf_u32_n[tid]] = (uint32_t)i_r;
-            d->buf_u32_t[tid][d->buf_u32_n[tid]] = (uint32_t)(hits[i]->tn);
-            d->buf_u32_n[tid]++;
+        d->counter++;
+        for (i=0; i<buf_len; i++){
+            hits[i]->del = 1;
+            delete_single_edge_both_dir(sources, coverage_cut, (uint32_t)i_r, hits[i]->tn);
             
         }
     }else if (need_to_protect==0){
@@ -3677,7 +3667,7 @@ static void hamt_hit_contained_worker(void *data, long i_r, int tid){  // callba
         sprintf(tmp_msg, "[debug::%s]     (there were %d contained reads)\n", __func__, (int)IDs_contained.n);
         hamt_dbgmsg_append(&msg, tmp_msg, strlen(tmp_msg));
     }
-    d->counter[tid]++;
+    d->counter++;
 
 finish:
     kv_destroy(buf);
@@ -3713,18 +3703,13 @@ void hamt_hit_contained_multi(ma_hit_t_alloc* sources, ma_hit_t_alloc* reverse_s
     aux.n_read = n_read;
     aux.readLen = readLen;
     aux.coverage_cut = coverage_cut;
-    aux.counter = (int*)calloc(asm_opt.thread_num, sizeof(int));
+    aux.counter = 0;
 
     kt_for(asm_opt.thread_num, hamt_hit_contained_worker, &aux, (long)n_read);
-    int total = 0;
-    for (int i=0; i<asm_opt.thread_num; i++){
-        total+=aux.counter[i];
-    }
-    free(aux.counter);
+    // kt_for(1, hamt_hit_contained_worker, &aux, (long)n_read);
 
     if (VERBOSE){
-        fprintf(stderr, "[M::%s] done, takes %0.2f s, treated %d spots; \n\n", __func__, Get_T()-startTime, total);
-        fflush(stderr);
+        fprintf(stderr, "[M::%s] done, takes %0.2f s, treated roughly %d spots; \n\n", __func__, Get_T()-startTime, aux.counter);
     }
 }
 
@@ -3732,53 +3717,20 @@ void hamt_hit_contained_drop_singleton_multi(ma_hit_t_alloc* sources, ma_hit_t_a
                         ma_sub_t *coverage_cut){
     double startTime = Get_T();
 
-    int init_buffer_size = 128;
     hitcontain_aux_t aux;
     aux.sources = sources;
     aux.reverse_sources = reverse_sources;
     aux.n_read = n_read;
     aux.readLen = readLen;
     aux.coverage_cut = coverage_cut;
-    aux.counter = (int*)calloc(asm_opt.thread_num, sizeof(int));
-    // init per thread linear buffers
-    aux.buf_u32_n = (int*)calloc(asm_opt.thread_num, sizeof(int));
-    aux.buf_u32_m = (int*)calloc(asm_opt.thread_num, sizeof(int));
-    aux.buf_u32_q = (uint32_t**)calloc(asm_opt.thread_num, sizeof(uint32_t*));
-    aux.buf_u32_t = (uint32_t**)calloc(asm_opt.thread_num, sizeof(uint32_t*));
-    for (int i=0; i<asm_opt.thread_num; i++){
-        aux.buf_u32_q[i] = (uint32_t*)calloc(init_buffer_size, sizeof(uint32_t));
-        aux.buf_u32_t[i] = (uint32_t*)calloc(init_buffer_size, sizeof(uint32_t));
-        aux.buf_u32_m[i] = init_buffer_size;
-    }
-
-    // collect
-    kt_for(asm_opt.thread_num, hamt_hit_contained_drop_singleton_worker_v2, &aux, (long)n_read);  // kt_for(asm_opt.thread_num, hamt_hit_contained_drop_singleton_worker, &aux, (long)n_read);
-    // delete
-    int total_del = 0;
-    for (int tid=0; tid<asm_opt.thread_num; tid++){
-        for (int j=0; j<aux.buf_u32_n[tid]; j++){
-            delete_single_edge_both_dir(sources, coverage_cut, aux.buf_u32_q[tid][j], aux.buf_u32_t[tid][j]);
-            total_del++;
-        }
-    }
-    
-    int total_incident = 0;
-    for (int i=0; i<asm_opt.thread_num; i++){
-        total_incident+=aux.counter[i];
-    }    
-    free(aux.counter);
-    for (int i=0; i<asm_opt.thread_num; i++){
-        free(aux.buf_u32_q[i]);
-        free(aux.buf_u32_t[i]);
-    }
-    free(aux.buf_u32_n);
-    free(aux.buf_u32_m);
-    free(aux.buf_u32_q);
-    free(aux.buf_u32_t);
-    
+    aux.counter = 0;
+
+    // kt_for(asm_opt.thread_num, hamt_hit_contained_drop_singleton_worker, &aux, (long)n_read);
+    kt_for(asm_opt.thread_num, hamt_hit_contained_drop_singleton_worker_v2, &aux, (long)n_read);
+    // kt_for(1, hamt_hit_contained_drop_singleton_worker_v2, &aux, (long)n_read);
+
     if (VERBOSE){
-        fprintf(stderr, "[M::%s] done, takes %0.2f s, treated %d spots (%d handles); \n\n", __func__, Get_T()-startTime, total_del, total_incident);
-        fflush(stderr);
+        fprintf(stderr, "[M::%s] done, takes %0.2f s, treated roughly %d spots; \n\n", __func__, Get_T()-startTime, aux.counter);
     }
 
 }
@@ -30253,7 +30205,7 @@ ma_sub_t **coverage_cut_ptr, int debug_g)
 
     renew_graph_init(sources, reverse_sources, sg, coverage_cut, ruIndex, n_read);
 
-    asm_opt.get_specific_overlap_is_use_bf = 1; sort_paf_buffers_by_targetID(sources, n_read); sort_paf_buffers_by_targetID(reverse_sources, n_read);
+    asm_opt.get_specific_overlap_is_use_bf = 0; /////sort_paf_buffers_by_targetID(sources, n_read); sort_paf_buffers_by_targetID(reverse_sources, n_read);
     
     // normalize_ma_hit_t_single_side_advance(sources, n_read);
     // normalize_ma_hit_t_single_side_advance(reverse_sources, n_read);
@@ -30269,7 +30221,7 @@ ma_sub_t **coverage_cut_ptr, int debug_g)
 
     ma_hit_sub(min_dp, sources, n_read, readLen, mini_overlap_length, &coverage_cut);
     
-    asm_opt.get_specific_overlap_is_use_bf = 1; sort_paf_buffers_by_targetID(sources, n_read); sort_paf_buffers_by_targetID(reverse_sources, n_read);
+    asm_opt.get_specific_overlap_is_use_bf = 0; //////sort_paf_buffers_by_targetID(sources, n_read); sort_paf_buffers_by_targetID(reverse_sources, n_read);
     detect_chimeric_reads_conservative(sources, n_read, readLen, coverage_cut, asm_opt.max_ov_diff_final * 2.0);  // detect_chimeric_reads(sources, n_read, readLen, coverage_cut, asm_opt.max_ov_diff_final * 2.0);
     ma_hit_cut(sources, n_read, readLen, mini_overlap_length, &coverage_cut);
     ma_hit_flt(sources, n_read, coverage_cut, max_hang_length, mini_overlap_length);
@@ -30278,7 +30230,7 @@ ma_sub_t **coverage_cut_ptr, int debug_g)
     hamt_hit_contained_multi(sources, reverse_sources, n_read, readLen, coverage_cut);
     hamt_hit_contained_drop_singleton_multi(sources, reverse_sources, n_read, readLen, coverage_cut);
 
-    asm_opt.get_specific_overlap_is_use_bf = 1; sort_paf_buffers_by_targetID(sources, n_read); sort_paf_buffers_by_targetID(reverse_sources, n_read);
+    asm_opt.get_specific_overlap_is_use_bf = 0; //////sort_paf_buffers_by_targetID(sources, n_read); sort_paf_buffers_by_targetID(reverse_sources, n_read);
     ma_hit_contained_advance(sources, n_read, coverage_cut, ruIndex, max_hang_length, mini_overlap_length);  // hamt_threaded_ma_hit_contained_advance(sources, n_read, coverage_cut, ruIndex);  // TODO
     asm_opt.get_specific_overlap_is_use_bf = 0;