--- a/src/pdps.rs	Wed Jul 22 16:48:22 2026 -0500
+++ b/src/pdps.rs	Sun Jul 26 17:30:51 2026 -0500
@@ -209,10 +209,10 @@
         prox_penalty.insert_and_reweigh(&mut μ, &mut τv, τ, ε, config, &reg, &state, &mut stats)?;
 
         // Prune and possibly merge spikes
-        if config.merge_now(&state) {
+        config.if_merge_now(&state, |ins| {
             stats.merged +=
-                prox_penalty.merge_spikes_no_fitness(&mut μ, &mut τv, &μ_base, τ, ε, config, &reg);
-        }
+                prox_penalty.merge_spikes_no_fitness(&mut μ, &mut τv, &μ_base, τ, ε, ins, &reg);
+        });
         stats.inserted += μ.len() - μ_base.len();
         stats.pruned += prune_with_stats(&mut μ);