Hey, I have an idea for an addition for Optifine.
I really hope you like the idea and go through with it because it'd be very handy for me and a few others. X3
So, I'm one of the lucky ducks to have a 4K screen, however my GPU isn't intended for games, so if I want to run shaders smoothly I usually set the resolution to 720p, because it still looks fine.
But... See, when I switch between shaders and regular 4K play I need to rescale the UI and change the mouse sensitivity to do that, which is annoying.
Do you think you could make setting profiles that we can make, save and switch between?
This would help a lot and seems to me like it'd be simple enough to make.
Play in 4k at all times, downsample when using shaders using the Render Quality option in the shaders menu.