My working notes Joy It 3.2 (Waveshare clone) display not working its messy and I tend to do it with command line parameters.
But since that mess I get it up and going ( admittedly with an inverted left/right
I have a small script touch.sh which sets it up after it’s all going.
It’s about the default settings for X but I’ve never got that fully understood.
Presumably the .99 files are read in order and this is just a sneaky way of installing a default, but presumably the zynths cut that off at the path somewhere back down the pipeline.