New source found from dndbeyond.com

ddb_main/packages/rules-engine/es/engine/Item/derivers.js

@@ -512,7 +512,7 @@ export function deriveWeaponReach(item, modifiers, ruleData) {
  * @param modifiers
  * @param martialArtsLevel
  */
-export function deriveAvailableWeaponAbilities(item, modifiers, martialArtsLevelScale, isDedicatedWeapon, isPactWeapon, isHexWeapon) {
+export function deriveAvailableWeaponAbilities(item, modifiers, martialArtsLevelScale, isDedicatedWeapon, isPactWeapon, isHexWeapon, appliedWeaponReplacementStats) {
     const availableAbilities = [];
     const attackType = getAttackType(item);
     if (attackType === AttackTypeRangeEnum.MELEE || hasWeaponProperty(item, WeaponPropertyEnum.FINESSE)) {
@@ -562,6 +562,22 @@ export function deriveAvailableWeaponAbilities(item, modifiers, martialArtsLevel
             });
         }
     }
+    //handle Weapon Replacement Stats
+    if (appliedWeaponReplacementStats.length > 0) {
+        const enableAbilityStatReplacementModifiers = modifiers.filter((modifier) => ModifierValidators.isReplaceWeaponAbilityModifier(modifier));
+        enableAbilityStatReplacementModifiers.forEach((modifier) => {
+            //get the origin of the modifier
+            const dataOrigin = ModifierAccessors.getDataOrigin(modifier);
+            if (dataOrigin) {
+                const replacementAbilities = deriveReplacementWeaponAbilities(modifiers, dataOrigin);
+                replacementAbilities.forEach((ability) => {
+                    if (!availableAbilities.includes(ability)) {
+                        availableAbilities.push(ability);
+                    }
+                });
+            }
+        });
+    }
     return availableAbilities;
 }
 export function deriveReplacementWeaponAbilities(modifiers, enableModifierDataOrigin) {