diff --git a/sound_algo/data_only/matrix.scd b/sound_algo/data_only/matrix.scd
index 0862e49..01dcb58 100644
--- a/sound_algo/data_only/matrix.scd
+++ b/sound_algo/data_only/matrix.scd
@@ -492,28 +492,27 @@ File.exists(~matDir).not.if({ ("mkdir -p " ++ ~matDir.quote).systemCmd });
 // Other dirs (e.g. shipped presets): scan via ls+tmpfile (systemCmd is
 // synchronous and works headless; pathMatch/Pipe.getLine are unreliable).
 ~matNames = { |dir|
-    (dir == ~matDir).if({
-        ~matSavedNames.asArray
-    }, {
-        var ext = ".matrix";
-        var result = [];
-        File.exists(dir).if({
-            var tmp = "/tmp/_av_live_matnames_.txt";
-            ("ls -1 '" ++ dir ++ "' > '" ++ tmp ++ "' 2>/dev/null").systemCmd;
-            File.exists(tmp).if({
-                var content = File.use(tmp, "r", { |f| f.readAllString });
-                ("rm -f '" ++ tmp ++ "'").systemCmd;
-                content.split($\n).do({ |fn|
-                    (fn.size > ext.size and: {
-                        fn.copyRange(fn.size - ext.size, fn.size - 1) == ext
-                    }).if({
-                        result = result.add(fn.copyRange(0, fn.size - ext.size - 1).asSymbol)
-                    })
+    var ext = ".matrix";
+    var result = [];
+    File.exists(dir).if({
+        var tmp = "/tmp/_av_live_matnames_.txt";
+        ("ls -1 '" ++ dir ++ "' > '" ++ tmp ++ "' 2>/dev/null").systemCmd;
+        File.exists(tmp).if({
+            var content = File.use(tmp, "r", { |f| f.readAllString });
+            ("rm -f '" ++ tmp ++ "'").systemCmd;
+            content.split($\n).do({ |fn|
+                (fn.size > ext.size and: {
+                    fn.copyRange(fn.size - ext.size, fn.size - 1) == ext
+                }).if({
+                    result = result.add(fn.copyRange(0, fn.size - ext.size - 1).asSymbol)
                 })
             })
-        });
-        result
-    })
+        })
+    });
+    // user dir: union the disk scan with in-memory saves (covers a just-saved
+    // name even if the fs scan races); other dirs: pure disk scan.
+    (dir == ~matDir).if({ result = (result ++ ~matSavedNames.asArray).as(Set).asArray });
+    result
 };
 
 // -- ~matGridPush : send full 512-int grid row-major to surfaces --
diff --git a/sound_algo/data_only/matrix_presets/test_matnames.scd b/sound_algo/data_only/matrix_presets/test_matnames.scd
new file mode 100644
index 0000000..27016b9
--- /dev/null
+++ b/sound_algo/data_only/matrix_presets/test_matnames.scd
@@ -0,0 +1,29 @@
+// Headless checks for ~matNames disk persistence + ~matWrapStep queued load.
+// Run: /Applications/SuperCollider.app/Contents/MacOS/sclang test_matnames.scd
+(
+var feat = PathName(thisProcess.nowExecutingPath).pathOnly ++ "../matrix.scd";
+var pass = true, dir, nm;
+~lp = (clock: TempoClock.default); ~toscSend = { |path ...a| }; ~toscTouch = { |a| };
+["kick","hats","clap","perc","sub","acid","arp","lead","stab","pad","ride","rim",
+ "tom","reese","bells","sweep","melody","chord","fx","snare","crash","shaker"].do { |v|
+    Pdef(("lp_" ++ v).asSymbol, Pbind(\instrument, v.asSymbol, \dur, 1)) };
+feat.load;
+
+// -- Part A: a .matrix on disk in ~matDir is listed even with an empty Set --
+dir = ~matDir; ("mkdir -p '" ++ dir ++ "'").systemCmd;
+File.use(dir +/+ "zz_persist_test.matrix", "w", { |f| f.write("('grid':[])") });
+~matSavedNames = Set.new;                      // simulate a fresh boot (no in-memory saves)
+nm = ~matNames.(dir);
+nm.includes(\zz_persist_test).not.if({ pass = false; "FAIL: ~matNames missed disk file".postln });
+("rm -f '" ++ (dir +/+ "zz_persist_test.matrix") ++ "'").systemCmd;
+
+// -- Part B: ~matWrapStep applies a queued load and clears the queue --
+~lp[\matrix] = Array.fill(~matVoices.size, { Array.fill(~matBars, 0) });
+~matQueuedLoad = "techno_drive_live";
+~matWrapStep.();
+(~matQueuedLoad.isNil).not.if({ pass = false; "FAIL: queue not cleared after wrap".postln });
+(~lp[\matrix].flatten.sum == 0).if({ pass = false; "FAIL: queued preset not loaded".postln });
+
+pass.if({ "MATNAMES PASS".postln }, { "MATNAMES FAIL".postln });
+0.exit;
+)