OpenGL (fake KMS) with Hyperpixel 4

Hi!
Why does my Hyperpixel show only a black screen if i activate the fake KMS on my Pi 3B+?.
I need OpenGl for some of my applications. Since it is a DPI screen it should be possible to activate FMKS…

Regards
Stefan

Same issue here with a Pi Zero-W. Once I enable fkms, the screen just doesn’t work :(

In short, can “dtoverlay=vc4-fkms-v3d” work with Hyperpixel 4 for anything that’s not a Raspberry Pi 4?

Thank you!