Was your customer Q8pilot? This is exactly his advice. He has you make a number of other changes too (mostly in nvidia) which did help me a little. I thought it was worth going through the exercise but I agree with you that it's a drop in the ocean aside from Game Mode. Good video. Thanks!
With my win11 i913900k/rtx4090 I don't see any significant difference in FPS performance with Game Mode on/off. I only see slightly less stuttering with it off. Another thing to test is turning on/off hardware acceleration graphics (HAGS). For best system stability I've always found it best to disable HAGS (with win11 it is on by default) for all my PCVR apps. As far as nvidia control panel goes, I leave everything default except power = prefer max performance and change the quality default below that to = high performance. Going into bios and disabling hyperthreading also helps keep cpu temps down a bit without any significant effect on performance. Like everything VR, yrmv, lol!
Have you ever tried experimenting with disabling "Core Isolation?" Or going into BIOS and disabling "Speedstep" and "Hyperthreading?" Supposedly, that can improve FPS...or make it worse. btw, I'd be interested to see an update in your version comparison. 12.1 not only looks great, but runs great, too.
Interesting. Even is game mode is enabled by default I'll check. What you said at the end of the video reminds me a tutorial about how to remove stutters in XPlane (nvidia settings)
Activating game mode caused a 4 FPS loss in Xplane 12 in the same scenario. My system is Intel 12400F, RTX 3060 with 32GB of memory. Windows 11 Pro I was disappointed that v12.1 in Xplane 12 did not improve the multi-core utilization. Most of the cores are idle.