diff --git a/Cargo.toml b/Cargo.toml
index 2b0e35e..d9b5dd9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,8 +16,6 @@ path = "src/main.rs"
 # increases perf at the cost of compile-time
 codegen-units = 1 # ~4-5% perf bump
 lto = true
-# incremental = false
-# overflow-checks = false
 
 [profile.profile]
 inherits = "release"
diff --git a/src/bitboard.rs b/src/bitboard.rs
index af75efb..bbda9d8 100644
--- a/src/bitboard.rs
+++ b/src/bitboard.rs
@@ -63,6 +63,8 @@ impl BitBoard {
         self.0 &= !(1 << index)
     }
 
+    // PERF! was going to optimize setting multiple indexes,
+    // seems rust does this for us: https://godbolt.org/z/ddj3dMxsP
     #[cfg(not(feature = "bitvec"))]
     const fn set_bit(&mut self, index: usize) {
         self.0 |= 1 << index
@@ -84,7 +86,7 @@ impl BitBoard {
 
     // works on both `bitvec` and native (const on native)
     #[const_fn(cfg(not(feature = "bitvec")))]
-    pub fn count(&self) -> usize {
+    pub const fn count(&self) -> usize {
         self.0.count_ones() as usize
     }
 }
diff --git a/src/board.rs b/src/board.rs
index a9d630e..58efbd1 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -63,6 +63,8 @@ fn gen_adj_lookup() -> PosMap<ChainCollection> {
                         "chains go out-of-bounds"
                     );
 
+                    // ensure all nodes in all chains are unique across chains, ensures beavior in
+                    // [`Board::propegate_from`]
                     let mut uniq = HashSet::new();
                     assert!(
                         chains.iter().flatten().all(move |x| uniq.insert(x)),
@@ -164,7 +166,8 @@ impl Board {
     }
 
     /// Starting position
-    pub fn starting_pos(mut self) -> Self {
+    #[const_fn(cfg(not(feature = "bitvec")))]
+    pub const fn starting_pos(mut self) -> Self {
         self.place_unchecked((BOARD_SIZE / 2) - 1, (BOARD_SIZE / 2) - 1, Piece::White);
         self.place_unchecked(BOARD_SIZE / 2, (BOARD_SIZE / 2) - 1, Piece::Black);
         self.place_unchecked((BOARD_SIZE / 2) - 1, BOARD_SIZE / 2, Piece::Black);
@@ -205,7 +208,7 @@ impl Board {
 
     /// Returns the color of a place on the [`Board`] at a position
     #[const_fn(cfg(not(feature = "bitvec")))]
-    pub fn get(&self, i: usize, j: usize) -> Option<Piece> {
+    pub const fn get(&self, i: usize, j: usize) -> Option<Piece> {
         if self.get_piece(i, j, Piece::White) {
             Some(Piece::White)
         } else if self.get_piece(i, j, Piece::Black) {
@@ -217,13 +220,13 @@ impl Board {
 
     /// Place a piece without checking for propegation of validity
     #[const_fn(cfg(not(feature = "bitvec")))]
-    fn place_unchecked(&mut self, i: usize, j: usize, piece: Piece) {
+    const fn place_unchecked(&mut self, i: usize, j: usize, piece: Piece) {
         self.board_mut(piece).set(i, j, true);
         self.board_mut(piece.flip()).set(i, j, false);
     }
 
     #[const_fn(cfg(not(feature = "bitvec")))]
-    fn delete(&mut self, i: usize, j: usize) {
+    const fn delete(&mut self, i: usize, j: usize) {
         self.board_mut(Piece::White).set(i, j, false);
         self.board_mut(Piece::Black).set(i, j, false);
     }
@@ -312,14 +315,14 @@ impl Board {
 
     /// Count the number of a type of [`Piece`] on the board
     #[const_fn(cfg(not(feature = "bitvec")))]
-    pub fn count(&self, piece: Piece) -> usize {
+    pub const fn count(&self, piece: Piece) -> usize {
         self.board(piece).count()
     }
 
     /// Get the "net score" of a player
     /// Formula: `net_score = Score_player - Score_opponent`
     #[const_fn(cfg(not(feature = "bitvec")))]
-    pub fn net_score(&self, piece: Piece) -> isize {
+    pub const fn net_score(&self, piece: Piece) -> isize {
         self.count(piece) as isize - self.count(piece.flip()) as isize
     }