Known performance issues regarding FPS, Frame Times and Vsyncs

I'm opening up this issue here so that others can share there experiences.

Some known issues you might run into are the following:

- Steam capped at 15, 30, or any other refresh rate that you wouldn't expect
- Games run fine, but when the overlay is opened the FPS is capped to 15,20,30 etc.
- Sudden frame time spikes that toggling between a random target back to off resolves
- Frame times remain high no matter what until you reboot the system
- Enabling/Disabling VRR can cause consistent frame time issues until you reboot
- The FPS limiter doesn't do anything when vsync isn't enabled in game like it does on the Steam Deck

Some or all of these issues are known to have issues on actual deck hardware when it's not running on SteamOS. When testing the neptune 6.1 kernel the issues go away.