Quick update: Managed to make it run a lot smoother using those parameters: dtoverlay=waveshare35a:rotate=270,swapxy=1,speed=27000000,fps=60. The higher the speed, the better it displays, but anything above 27000000 f'd up the colors badly for me. Definitely playable for anyone wanting to use this screen, but it still drops some frames, mainly during cinematics and stuff. Personally, Gonna try out a 5" HDMI screen, don't wanna compromise on the gaming experience too much.