diff --git a/docs/WIDESCREEN.md b/docs/WIDESCREEN.md
index 710624cb..f5cad96a 100644
--- a/docs/WIDESCREEN.md
+++ b/docs/WIDESCREEN.md
@@ -130,7 +130,8 @@ User has visually confirmed: world geometry, characters, HUD, menus, FMVs, and
 proportions on the 16:9 stretch.
 
 **Live diagnostics (TCP debug server, committed `1e28a94`/earlier):**
-`ws_aspect num den` (toggle the GTE squash on/off in place — `1 1` = off),
+`ws_aspect num den` (set the GTE squash for a target aspect in place: `4 3` = off/identity, `16 9` = 0.75x;
+note `1 1` is NOT off, it expands X by 4/3),
 `ws_far_threshold [t]` (set the SZ depth split + read the backdrop driver's SZ
 stats so the split is data-driven), `ws_census on|off|<start> <end>` (always-on
 per-prim draw ring → CSV), `ws_margin <v|-1>` (force the cull margin), and the
diff --git a/runtime/include/gpu.h b/runtime/include/gpu.h
index c7ad881f..df0c92bc 100644
--- a/runtime/include/gpu.h
+++ b/runtime/include/gpu.h
@@ -527,7 +527,9 @@ void gpu_ws_tag_hud_prim_projected(uint32_t prim, int anchor);
  * GTE reports each SXY it produces; a title plugin asks whether a packet
  * vertex is one of them, i.e. whether the game built that primitive from
  * projected geometry (its X is already squashed) rather than authored
- * screen coordinates. Recorded only while the squash is engaged. */
+ * screen coordinates. Opt-in (gpu_ws_set_gte_sxy_tracking) and recorded
+ * only while the squash is engaged. */
+void gpu_ws_set_gte_sxy_tracking(int on);
 void gpu_ws_note_gte_sxy(int32_t x, int32_t y);
 int gpu_ws_gte_sxy_recent(int32_t x, int32_t y);
 /* Stretch a trusted authored background primitive about the display center in
diff --git a/runtime/include/mod_plugins.h b/runtime/include/mod_plugins.h
index 9ad2122b..cc9b8934 100644
--- a/runtime/include/mod_plugins.h
+++ b/runtime/include/mod_plugins.h
@@ -371,6 +371,10 @@ void psx_mod_anchor_hud_primitive_projected(uint32_t primitive, int edge);
  * yes was built from projected geometry (already squashed); one that does not
  * carries authored screen coordinates. Always 0 while the squash is off. */
 int psx_mod_gte_sxy_recent(int32_t x, int32_t y);
+/* Opt in to (1) or out of (0) the recent-projection record behind
+ * psx_mod_gte_sxy_recent. Off by default: until a plugin enables it nothing is
+ * recorded and the query answers 0. Call from an activation callback. */
+void psx_mod_set_gte_sxy_tracking(int enabled);
 /* Screen-space masks identified by their title's producer, P_TAG addresses.
  * Flat panels extend only their exterior boundaries. Radial flat/Gouraud
  * quads scale around the display centre for an aspect-aware iris transition.
diff --git a/runtime/src/gpu.c b/runtime/src/gpu.c
index 2733250f..b496c7b1 100644
--- a/runtime/src/gpu.c
+++ b/runtime/src/gpu.c
@@ -2583,13 +2583,18 @@ static void ws_tag_stats_note_lookup(GpuWsTagStats *stats, int result) {
 }
 
 /* Positions the GTE projected this and the previous vblank (ws_gte_sxy.h).
- * Only recorded while the squash is engaged: nothing else reads it. */
+ * Opt-in: nothing is recorded (and every query answers no) until a title
+ * plugin enables it, and only while the squash is engaged, so titles that do
+ * not use the query pay nothing and see no change. */
 static WsGteSxy ws_gte_sxy;
+static int ws_gte_sxy_tracking;   /* opt-in: a title plugin turns it on */
+void gpu_ws_set_gte_sxy_tracking(int on) { ws_gte_sxy_tracking = on ? 1 : 0; }
 void gpu_ws_note_gte_sxy(int32_t x, int32_t y) {
-    if (!ws_active()) return;
+    if (!ws_gte_sxy_tracking || !ws_active()) return;
     ws_gte_sxy_note(&ws_gte_sxy, (uint32_t)s_frame_count, x, y);
 }
 int gpu_ws_gte_sxy_recent(int32_t x, int32_t y) {
+    if (!ws_gte_sxy_tracking) return 0;
     return ws_gte_sxy_recent(&ws_gte_sxy, (uint32_t)s_frame_count, x, y);
 }
 
diff --git a/runtime/src/mod_runtime.cpp b/runtime/src/mod_runtime.cpp
index e17f0eec..cf1a23b4 100644
--- a/runtime/src/mod_runtime.cpp
+++ b/runtime/src/mod_runtime.cpp
@@ -3469,6 +3469,9 @@ extern "C" void psx_mod_tag_hud_primitive(uint32_t primitive, int edge) {
 extern "C" void psx_mod_anchor_hud_primitive(uint32_t primitive, int edge) {
     gpu_ws_tag_hud_prim(primitive, edge);
 }
+extern "C" void psx_mod_set_gte_sxy_tracking(int enabled) {
+    gpu_ws_set_gte_sxy_tracking(enabled);
+}
 extern "C" int psx_mod_gte_sxy_recent(int32_t x, int32_t y) {
     return gpu_ws_gte_sxy_recent(x, y);
 }
diff --git a/runtime/tests/test_mod_resident.cpp b/runtime/tests/test_mod_resident.cpp
index 0cc057b1..e8be7b65 100644
--- a/runtime/tests/test_mod_resident.cpp
+++ b/runtime/tests/test_mod_resident.cpp
@@ -60,6 +60,9 @@ extern "C" void gpu_get_display_info(GpuDisplayInfo* out) { *out = GpuDisplayInf
 extern "C" void dirty_ram_mark_executable_range(uint32_t, uint32_t) {}
 extern "C" int fntrace_is_game_started(void) { return 1; }
 extern "C" void gpu_ws_tag_hud_primitive(uint32_t, int) {}
+extern "C" void gpu_ws_tag_hud_prim_projected(uint32_t, int) {}
+extern "C" void gpu_ws_set_gte_sxy_tracking(int) {}
+extern "C" int gpu_ws_gte_sxy_recent(int32_t, int32_t) { return 0; }
 extern "C" void gpu_ws_tag_world_primitive(uint32_t, int) {}
 extern "C" void gpu_ws_set_adaptive_backdrop_preload(int) {}
 extern "C" int gpu_ws_configured_x_reveal(void) { return 0; }
diff --git a/runtime/tests/test_mod_runtime.cpp b/runtime/tests/test_mod_runtime.cpp
index 5e5e7b08..366654e1 100644
--- a/runtime/tests/test_mod_runtime.cpp
+++ b/runtime/tests/test_mod_runtime.cpp
@@ -192,6 +192,9 @@ static int test_disc_request(int *ready) { ++disc_request_calls; *ready = 1; ret
 static void test_disc_request_activate(void) { psx_mod_set_disc_request_provider(test_disc_request); }
 /* Widescreen tag passthroughs mod_runtime forwards to the GPU; unused here. */
 extern "C" void gpu_ws_tag_hud_primitive(uint32_t, int) {}
+extern "C" void gpu_ws_tag_hud_prim_projected(uint32_t, int) {}
+extern "C" void gpu_ws_set_gte_sxy_tracking(int) {}
+extern "C" int gpu_ws_gte_sxy_recent(int32_t, int32_t) { return 0; }
 extern "C" void gpu_ws_tag_world_primitive(uint32_t, int) {}
 extern "C" void gpu_ws_set_adaptive_backdrop_preload(int) {}
 extern "C" int gpu_ws_configured_x_reveal(void) { return 0; }
diff --git a/runtime/tests/test_netplay_view_mods.cpp b/runtime/tests/test_netplay_view_mods.cpp
index 3c3b6b1b..e1787d2f 100644
--- a/runtime/tests/test_netplay_view_mods.cpp
+++ b/runtime/tests/test_netplay_view_mods.cpp
@@ -156,6 +156,9 @@ extern "C" void dirty_ram_mark_executable_range(uint32_t, uint32_t) {}
 extern "C" int fntrace_is_game_started(void) { return 1; }
 /* Widescreen tag passthroughs mod_runtime forwards to the GPU; unused here. */
 extern "C" void gpu_ws_tag_hud_primitive(uint32_t, int) {}
+extern "C" void gpu_ws_tag_hud_prim_projected(uint32_t, int) {}
+extern "C" void gpu_ws_set_gte_sxy_tracking(int) {}
+extern "C" int gpu_ws_gte_sxy_recent(int32_t, int32_t) { return 0; }
 extern "C" void gpu_ws_tag_world_primitive(uint32_t, int) {}
 extern "C" void gpu_ws_set_adaptive_backdrop_preload(int) {}
 extern "C" int gpu_ws_configured_x_reveal(void) { return 0; }
diff --git a/runtime/tests/test_pgxp_session.cpp b/runtime/tests/test_pgxp_session.cpp
index 33321813..41f6feb5 100644
--- a/runtime/tests/test_pgxp_session.cpp
+++ b/runtime/tests/test_pgxp_session.cpp
@@ -135,6 +135,9 @@ extern "C" void gpu_get_display_info(GpuDisplayInfo* out) { *out = GpuDisplayInf
 extern "C" void dirty_ram_mark_executable_range(uint32_t, uint32_t) {}
 extern "C" int fntrace_is_game_started(void) { return 1; }
 extern "C" void gpu_ws_tag_hud_primitive(uint32_t, int) {}
+extern "C" void gpu_ws_tag_hud_prim_projected(uint32_t, int) {}
+extern "C" void gpu_ws_set_gte_sxy_tracking(int) {}
+extern "C" int gpu_ws_gte_sxy_recent(int32_t, int32_t) { return 0; }
 extern "C" void gpu_ws_tag_world_primitive(uint32_t, int) {}
 extern "C" void gpu_ws_set_adaptive_backdrop_preload(int) {}
 extern "C" void psx_projection_reset_session(void) {}