diff -r 4f468d35fa29 -r 7a8a55fd41c0 src/prox_penalty.rs
--- a/src/prox_penalty.rs	Thu Feb 26 11:38:43 2026 -0500
+++ b/src/prox_penalty.rs	Thu Feb 26 11:36:22 2026 -0500
@@ -129,17 +129,15 @@
     /// May return `τv + w` for `w` a subdifferential of the regularisation term `reg`,
     /// as well as an indication of whether the tolerance bounds `ε` are satisfied.
     ///
-    /// `μ_base + ν_delta` is the base point, where `μ` and `μ_base` are assumed to have the same
-    /// spike locations, while `ν_delta` may have different locations.
-    ///
     /// `τv` is mutable to allow [`alg_tools::bounds::MinMaxMapping`] optimisation to
     /// refine data. Actual values of `τv` are not supposed to be mutated.
+    ///
+    /// `stats.inserted` should not be updated by implementations of this routine,
+    /// only `stats.inner_iters`.
     fn insert_and_reweigh<I>(
         &self,
         μ: &mut DiscreteMeasure<Domain, F>,
         τv: &mut PreadjointCodomain,
-        μ_base: &DiscreteMeasure<Domain, F>,
-        ν_delta: Option<&DiscreteMeasure<Domain, F>>,
         τ: F,
         ε: F,
         config: &InsertionConfig<F>,
@@ -160,7 +158,6 @@
         μ: &mut DiscreteMeasure<Domain, F>,
         τv: &mut PreadjointCodomain,
         μ_base: &DiscreteMeasure<Domain, F>,
-        ν_delta: Option<&DiscreteMeasure<Domain, F>>,
         τ: F,
         ε: F,
         config: &InsertionConfig<F>,
@@ -177,7 +174,6 @@
         μ: &mut DiscreteMeasure<Domain, F>,
         τv: &mut PreadjointCodomain,
         μ_base: &DiscreteMeasure<Domain, F>,
-        ν_delta: Option<&DiscreteMeasure<Domain, F>>,
         τ: F,
         ε: F,
         config: &InsertionConfig<F>,
@@ -193,7 +189,6 @@
             μ,
             τv,
             μ_base,
-            ν_delta,
             τ,
             ε,
             config,