diff --git a/apps/effectcraft/src/main.rs b/apps/effectcraft/src/main.rs
index 38a88b3d..2f99bd5e 100644
--- a/apps/effectcraft/src/main.rs
+++ b/apps/effectcraft/src/main.rs
@@ -93,6 +93,9 @@ fn parse_args(args: impl IntoIterator<Item = String>, env_port: Result<String, s
             "--version" => return Ok(None),
             _ => match a.strip_prefix("--control=") {
                 Some(v) => out.control_port = Some(control_port("--control", Some(v))?),
+                // macOS LaunchServices may pass a process serial number (`-psn_0_1234`), notably on
+                // the first launch of a downloaded app; it is not an option of ours.
+                None if a.starts_with("-psn_") => {}
                 None if a.starts_with('-') && a != "-" => return Err(format!("unknown option `{a}`")),
                 None => out.files.push(a),
             },
@@ -494,7 +497,7 @@ mod tests {
         assert!(super::wayland_drop_notice(Some(OsStr::new("wayland-0")), Some(OsStr::new("x11"))).is_none());
     }
 
-    /// The window's device never asks for more than the adapter offers (#198).
+    /// The window's wgpu instance skips indirect-call validation (Intel Metal, #1153).
     #[test]
     fn the_window_instance_skips_indirect_call_validation() {
         if std::env::var_os("WGPU_VALIDATION_INDIRECT_CALL").is_some() {
@@ -507,6 +510,7 @@ mod tests {
         assert!(!setup.instance_descriptor.flags.contains(eframe::wgpu::InstanceFlags::VALIDATION_INDIRECT_CALL));
     }
 
+    /// The window's device never asks for more than the adapter offers (#198).
     #[test]
     fn device_limits_fit_the_adapter() {
         use eframe::wgpu::Limits;
@@ -569,6 +573,8 @@ mod tests {
         }
         // Parsed left to right: an error before `--version` wins.
         assert_eq!(fails(&["--nope", "--version"]), "unknown option `--nope`");
+        // Finder's process serial number is ignored, not imported or refused.
+        assert_eq!(parse(&["-psn_0_12345"]).map(|a| a.files), Some(vec![]));
         let a = parse(&["clip.mov", "-", "--", "--demo", "-name.png"]).unwrap_or_default();
         assert_eq!(a.files, ["clip.mov", "-", "--demo", "-name.png"]);
         assert!(!a.demo);
diff --git a/crates/effects/src/channel3d.rs b/crates/effects/src/channel3d.rs
index 893bef20..0d089ba2 100644
--- a/crates/effects/src/channel3d.rs
+++ b/crates/effects/src/channel3d.rs
@@ -386,7 +386,7 @@ type RankPlanes<'a> = [(&'a [f32], &'a [f32])];
 /// ranks (the Cryptomatte spec's matte), clamped to 0..1.
 #[inline]
 fn crypto_matte(planes: &RankPlanes, sel: &[u32], i: usize) -> f32 {
-    planes.iter().map(|(id, c)| (id[i], c[i])).filter(|(id, c)| *c > 0.0 && sel.contains(&id.to_bits())).map(|(_, c)| c).sum::<f32>().clamp(0.0, 1.0)
+    planes.iter().filter_map(|(id, c)| Some((*id.get(i)?, *c.get(i)?))).filter(|(id, c)| *c > 0.0 && sel.contains(&id.to_bits())).map(|(_, c)| c).sum::<f32>().clamp(0.0, 1.0)
 }
 
 /// The coverage-weighted ID colours at aux pixel `i` (the spec's preview).
@@ -394,7 +394,7 @@ fn crypto_matte(planes: &RankPlanes, sel: &[u32], i: usize) -> f32 {
 fn crypto_colors(planes: &RankPlanes, i: usize) -> [f32; 3] {
     let mut c = [0.0f32; 3];
     for (id, cov) in planes {
-        let (id, cov) = (id[i], cov[i]);
+        let (Some(&id), Some(&cov)) = (id.get(i), cov.get(i)) else { continue };
         let k = id_color(id);
         for j in 0..3 {
             c[j] += k[j] * cov;
diff --git a/crates/engine/src/commands/layer_menu.rs b/crates/engine/src/commands/layer_menu.rs
index 7685d6bf..7737b8af 100644
--- a/crates/engine/src/commands/layer_menu.rs
+++ b/crates/engine/src/commands/layer_menu.rs
@@ -557,7 +557,6 @@ fn add_marker(s: &mut Session, p: &Value) -> Result<Value> {
     if ids.is_empty() {
         s.edit("Add Marker", None, |proj, _| {
             let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-            c.markers.retain(|m| m.time != t);
             c.markers.push(Marker { time: t, comment, ..Default::default() });
             c.markers.sort_by_key(|m| m.time);
             Ok(())
diff --git a/crates/script/src/model.rs b/crates/script/src/model.rs
index e4bf127d..90b03ae5 100644
--- a/crates/script/src/model.rs
+++ b/crates/script/src/model.rs
@@ -94,9 +94,6 @@ fn label_index(l: Label) -> usize {
     Label::ALL.iter().position(|x| *x == l).unwrap_or(0)
 }
 
-/// A comp's selected properties as `[layer, uid]`: the selected ones, then those with selected
-/// keyframes (selecting a keyframe selects its property in After Effects, so scripts find
-/// selected keys through `selectedProperties`).
 /// Layer ids selected in `comp`, including a comp that is not the active one (#1001).
 fn selected_layer_ids(s: &Session, comp: effectcraft_project::ItemId) -> Vec<u64> {
     let layers = if s.active_comp_id() == Some(comp) {
@@ -118,6 +115,9 @@ fn layer_selected(s: &Session, comp: effectcraft_project::ItemId, layer: effectc
     s.state.comp_selections.get(&comp).is_some_and(|sel| sel.layers.contains(&layer))
 }
 
+/// A comp's selected properties as `[layer, uid]`: the selected ones, then those with selected
+/// keyframes (selecting a keyframe selects its property in After Effects, so scripts find
+/// selected keys through `selectedProperties`).
 fn selected_props(s: &Session, c: &effectcraft_project::Comp) -> Vec<J> {
     let mut v: Vec<(u64, u64)> = vec![];
     let keyed = s.state.selected_keys.iter().map(|k| (k.layer, k.prop));