diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c9c1eccc..cf4e2368 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,6 +22,7 @@ jobs:
         run: |
           cargo test --all-features
           cargo test --release --all-features
+          cargo bench
 
   msrv_test_suite:
     runs-on: ubuntu-latest
diff --git a/starlight/src/ensemble/state.rs b/starlight/src/ensemble/state.rs
index ce52eb64..446c085c 100644
--- a/starlight/src/ensemble/state.rs
+++ b/starlight/src/ensemble/state.rs
@@ -12,7 +12,10 @@ use awint::awint_dag::{
 use super::{Referent, Value};
 use crate::{
     awi,
-    ensemble::{Ensemble, PBack},
+    ensemble::{
+        value::{Change, Eval},
+        Ensemble, PBack,
+    },
     epoch::EpochShared,
 };
 
@@ -130,6 +133,23 @@ impl Ensemble {
                     let source = self.stator.states[p_state].op.operands()[i];
                     self.dec_rc(source).unwrap();
                 }
+                // if the `op` is manually replaced outside of the specially handled lowering
+                // `Copy` replacements, we need to check the values or else this change could be
+                // lost if this was done after initializing `p_self_bits`
+                let state = &mut self.stator.states[p_state];
+                if !state.p_self_bits.is_empty() {
+                    assert_eq!(state.p_self_bits.len(), x.bw());
+                    for i in 0..x.bw() {
+                        if let Some(p_bit) = state.p_self_bits[i] {
+                            let p_equiv = self.backrefs.get_val(p_bit).unwrap().p_self_equiv;
+                            self.evaluator.insert(Eval::Change(Change {
+                                depth: 0,
+                                p_equiv,
+                                value: Value::Const(x.get(i).unwrap()),
+                            }));
+                        }
+                    }
+                }
                 self.stator.states[p_state].op = Literal(x);
                 Ok(())
             }
diff --git a/starlight/src/ensemble/value.rs b/starlight/src/ensemble/value.rs
index e0750874..1f586c59 100644
--- a/starlight/src/ensemble/value.rs
+++ b/starlight/src/ensemble/value.rs
@@ -88,16 +88,16 @@ pub enum EvalPhase {
 
 #[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct RequestTNode {
-    depth: i64,
-    number_a: u8,
-    p_back_tnode: PBack,
+    pub depth: i64,
+    pub number_a: u8,
+    pub p_back_tnode: PBack,
 }
 
 #[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Change {
-    depth: i64,
-    p_equiv: PBack,
-    value: Value,
+    pub depth: i64,
+    pub p_equiv: PBack,
+    pub value: Value,
 }
 
 #[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
@@ -430,7 +430,13 @@ impl Ensemble {
             Eval::Change(change) => {
                 let equiv = self.backrefs.get_val_mut(change.p_equiv).unwrap();
                 equiv.change_visit = self.evaluator.change_visit_gen();
-                equiv.val = change.value;
+                // Handles a rare case where the evaluator decides to change to a const, and
+                // something later tries to set it to an unknown. TODO not sure if this is a bug
+                // that should be resolved some other way, the relevant part is where `Change`s
+                // are pushed in `eval_state`.
+                if !equiv.val.is_const() {
+                    equiv.val = change.value;
+                }
                 let mut adv = self.backrefs.advancer_surject(change.p_equiv);
                 while let Some(p_back) = adv.advance(&self.backrefs) {
                     let referent = *self.backrefs.get_key(p_back).unwrap();
diff --git a/testcrate/src/lib.rs b/testcrate/src/lib.rs
index 22162f35..806fa525 100644
--- a/testcrate/src/lib.rs
+++ b/testcrate/src/lib.rs
@@ -2,6 +2,6 @@ use std::path::PathBuf;
 
 use starlight::{awint_dag::EvalError, Epoch};
 
-fn _render(epoch: &Epoch) -> Result<(), EvalError> {
+pub fn _render(epoch: &Epoch) -> Result<(), EvalError> {
     epoch.render_to_svgs_in_dir(PathBuf::from("./".to_owned()))
 }
diff --git a/testcrate/tests/fuzz_lower.rs b/testcrate/tests/fuzz_lower.rs
index 9cd79fcd..ac1fe316 100644
--- a/testcrate/tests/fuzz_lower.rs
+++ b/testcrate/tests/fuzz_lower.rs
@@ -1,3 +1,5 @@
+// This is copied from `fuzzing` in `awint` and should be kept up to date
+
 use std::{
     cmp::{max, min},
     num::NonZeroUsize,
@@ -16,12 +18,10 @@ use starlight::{
 };
 
 // miri is just here to check that the unsized deref hacks are working
-const N: (u32, u32) = if cfg!(miri) {
-    (1, 1)
-} else if cfg!(debug_assertions) {
-    (32, 100)
+const N: (u32, u32) = if cfg!(debug_assertions) {
+    (32, 30)
 } else {
-    (32, 1000)
+    (32, 300)
 };
 
 ptr_struct!(P0);