I was already making this experience and found also a video conforming it.
The Pi is not able to handle display resolutions higher as 240x320, because
of the increased data transfer and it will manifest with very low frame rates.
Only solution that will help, but not resolve completly is to replace the waveshare
driver by the fbcp-ili9341 if the display electronics will allow. It is working for
most. This driver has a totaly different sapproach, as he just write the changed
areas back to the display. Some video https://www.youtube.com/watch?v=8bazEcXemiA
The fbcp-ili9341 is to recommend anyway, as it can easy not only rotate the display
area, but also move the center or crop, expand if the box frame hide some of the
This is now really my last post in this forum.