Direct access for realtime updates

It seems that if I draw a diagonal line across the screen the full screen gets updated, and this is very slow. Is there a way to access the display in the same way this lib does it? https://github.com/aguaviva/ili9342c_mpy it should be much faster

The goal is to achieve drawing a spark line in full screen, with some text, at 20 FPS or more. 