Freeplay CM4

[Flavor]

Also, did you try the one at https://github.com/TheFlav/rpi-fbcp
It should be really simple, and it might give a good baseline to see if it just works. You'd have to add this line back in, to use it.
dtoverlay=waveshare32b,speed=80000000,fps=60,rotate=270

In theory, you could just edit the config.txt and ...

cd ~/Freeplay
git clone https://github.com/TheFlav/rpi-fbcp.git
cd rpi-fbcp
./install.sh
sudo reboot