docs(perf): add owner report, run-3 results and player tuning notes

analysis/client-perf/PLAYER-TUNING.md

@@ -49,7 +49,8 @@ extra in multiplayer. Distant Horizons draws everything beyond that.
 ## 2. Java memory and garbage collector (Prism → Edit Instance → Settings → Java)
 
 Use **Java 21** (Temurin 21 recommended). More memory is *not* faster: a bigger heap makes
-each GC pause longer.
+each GC pause longer. Bench (B4h): **5 GB is enough; 4 GB is measurably worse** (tour 1 % low
+−23 fps); 6 and 8 GB were no faster than 5. Don't go below 5 GB on any machine.
 
 | Your machine | Max memory (`-Xmx`) | Min memory |
 | --- | --- | --- |
@@ -82,8 +83,10 @@ Don't add `-XX:+AlwaysPreTouch` on the Deck or on low-RAM PCs. Don't copy
 *Pending the owner's shader policy. Interim advice:* **shaders off** is the pack default.
 They cost more in this pack than usual:
 
-- With any shaderpack on, **Create's GPU renderer (Flywheel) switches off**, so every
-  rotating shaft and machine is drawn the slow way, and drawn again for shadows.
+- On its own, Flywheel (Create's GPU renderer) **switches off when any shaderpack is on**.
+  The pack now ships **Iris Flywheel Compat**, which keeps it working under shaders (bench:
+  Create floor p99 13.3 → 4.0 ms with MakeUp). It's unofficial, so it may lag behind
+  Create/Iris updates; if Create machines render wrong with shaders, report it.
 - Shader **shadows corrupt airships** (Sable sub-levels; Iris issue #3164).
 - Distant Horizons adds a shadow pass over all its terrain.