80000000 works fine on my pitft, I can’t discern any glitches, flashes or flickers. There’s little or no input lag. I went with the adafruit settings purely because that’s what they recommended for the 2.8 screens and they seem to work fine with my 3.5. Regarding the fps – I’m not sure why there’s an fps setting however I was happy enough to stick with 60fps as it correlates with the refresh rate of most of the emulators I’m using. I’m not sure why a tft would have both a refresh and an fps setting though.