how’s your linux kung-fu?
You’ll need to manually install a bunch of Python stuff (as outlined on the patchstorage page).
Then you need to deal with the pi4 dynamically allocating the video framebuffers - once you plug in an HDMI screen, I believe that one becomes fb0 and will get the Fates display output. So you would need to make a few adjustments to have the on-device OLED on fb1. Pi3b+ would actually be easier as the HDMI is always on fb0 and Fates is set to use fb1
Does not look easy or straightforward off the top of my head.