diff --git a/js/ltx_director.js b/js/ltx_director.js
index fba2cb9..d101a47 100644
--- a/js/ltx_director.js
+++ b/js/ltx_director.js
@@ -53,7 +53,15 @@ function stripAudioSegmentTransient(s) {
 }
 
 function dedupeById(items = []) {
-  return items.filter((seg, index, self) => index === self.findIndex((s) => s.id === seg.id));
+  const seen = new Set();
+  const deduped = [];
+  for (const seg of items || []) {
+    const id = seg?.id;
+    if (!id || seen.has(id)) continue;
+    seen.add(id);
+    deduped.push(seg);
+  }
+  return deduped;
 }
 
 function findActiveSegmentAtFrame(segments = [], targetFrame, type) {
@@ -61,6 +69,10 @@ function findActiveSegmentAtFrame(segments = [], targetFrame, type) {
     (seg) => seg?.type === type && targetFrame >= seg.start && targetFrame < seg.start + seg.length
   );
 }
+
+function segmentMatchesAudioSource(seg, audioFile, blobUrl) {
+  return !!seg && (seg.audioFile === audioFile || seg._blobUrl === blobUrl);
+}
 
 function hideWidget(w) {
   if (!w) return;
@@ -2004,6 +2016,14 @@ class TimelineEditor {
     return found;
   }
 
+  _forEachMatchingAudioSegment(audioFile, blobUrl, visitor) {
+    for (const seg of this.timeline.audioSegments || []) {
+      if (segmentMatchesAudioSource(seg, audioFile, blobUrl)) {
+        visitor(seg);
+      }
+    }
+  }
+
   _getSegmentsByFileKey(fileKey) {
     const matches = [];
     this._forEachMatchingSegment(fileKey, (seg) => {
@@ -2231,11 +2251,10 @@ class TimelineEditor {
 
       const audioBuffer = await this._loadAudioBuffer(seg);
 
-      const matchingSegs = this.timeline.audioSegments.filter(s => s.audioFile === seg.audioFile || s._blobUrl === seg._blobUrl);
-      for (const s of matchingSegs) {
-        s._audioBuffer = audioBuffer;
-        s._decoding = false;
-      }
+      this._forEachMatchingAudioSegment(seg.audioFile, seg._blobUrl, (s) => {
+        s._audioBuffer = audioBuffer;
+        s._decoding = false;
+      });
     } catch (err) {
       console.warn("Failed to preload audio segment:", err);
       seg._decoding = false;
diff --git a/ltx_director.py b/ltx_director.py
index 61392a6..cd0bebc 100644
--- a/ltx_director.py
+++ b/ltx_director.py
@@ -32,7 +32,12 @@ from .prompt_relay import (
 
 from .patches import detect_model_type, apply_patches
 
-log = logging.getLogger(__name__)
+log = logging.getLogger(__name__)
+CHARACTER_TAG_GROUPS = (
+    ("@character1", "@char1"),
+    ("@character2", "@char2"),
+    ("@character3", "@char3"),
+)
 
 # Setup global event loop exception handler to silence ConnectionResetError (WinError 10054/10053) on Windows
 try:
@@ -281,40 +286,26 @@ def _time_range_to_latent_indices(rel_start_frames: float, rel_length_frames: fl
     return start_idx, end_idx
 
 
-def _preprocess_prompts_with_characters(global_prompt, local_prompts, char1="", char2="", char3=""):
-    """Invisibly swaps out @character1/@char1 tags with their high-fidelity VLM descriptions."""
-    gp = global_prompt or ""
-    char1 = char1 if char1 else ""
-    char2 = char2 if char2 else ""
-    char3 = char3 if char3 else ""
-
-    # Process Global Prompt
-    for tag in ["@character1", "@char1"]:
-        if tag in gp:
-            gp = gp.replace(tag, char1)
-    for tag in ["@character2", "@char2"]:
-        if tag in gp:
-            gp = gp.replace(tag, char2)
-    for tag in ["@character3", "@char3"]:
-        if tag in gp:
-            gp = gp.replace(tag, char3)
-
-    # Process Local Timeline Prompts
-    locals_list = [p.strip() for p in local_prompts.split("|")] if local_prompts else []
-    processed_locals = []
-    for lp in locals_list:
-        for tag in ["@character1", "@char1"]:
-            if tag in lp:
-                lp = lp.replace(tag, char1)
-        for tag in ["@character2", "@char2"]:
-            if tag in lp:
-                lp = lp.replace(tag, char2)
-        for tag in ["@character3", "@char3"]:
-            if tag in lp:
-                lp = lp.replace(tag, char3)
-        processed_locals.append(lp)
-
-    return gp, " | ".join(processed_locals)
+def _preprocess_prompts_with_characters(global_prompt, local_prompts, char1="", char2="", char3=""):
+    """Invisibly swaps out @character1/@char1 tags with their high-fidelity VLM descriptions."""
+    replacements = {}
+    for tags, value in zip(CHARACTER_TAG_GROUPS, (char1 or "", char2 or "", char3 or "")):
+        for tag in tags:
+            replacements[tag] = value
+
+    def apply_replacements(text: str) -> str:
+        updated = text or ""
+        for tag, replacement in replacements.items():
+            if tag in updated:
+                updated = updated.replace(tag, replacement)
+        return updated
+
+    gp = apply_replacements(global_prompt or "")
+    if not local_prompts:
+        return gp, ""
+
+    processed_locals = [apply_replacements(part.strip()) for part in local_prompts.split("|")]
+    return gp, " | ".join(processed_locals)
 
 
 def _load_image_source(b64_or_url: str, filename: str = None, cache: dict | None = None,
@@ -1391,8 +1382,7 @@ def _build_reference_mode_outputs(
             raise ValueError("Licon MSR (Prefix) ref option requires connecting the VAE to LTX Director!")
 
         prompt_text = (global_prompt or "") + " " + (local_prompts or "")
-        tag_pairs = [("@character1", "@char1"), ("@character2", "@char2"), ("@character3", "@char3")]
-        referenced_slots = [i for i, tags in enumerate(tag_pairs) if any(t in prompt_text for t in tags)]
+        referenced_slots = [i for i, tags in enumerate(CHARACTER_TAG_GROUPS) if any(t in prompt_text for t in tags)]
         selected = []
         for slot in referenced_slots:
             if slot < len(char_slot_images):