I wrote a gui app once that ran on a safety-critical platform. I ended up stuffing a rendering of the gui (rendered offscreen) into shmem at I think 24hz, and rendered that screenshot into the safety critical application. I passed clicks (no typing for this gui) back from the statically rendered image updating on a cadence, to the offscreen GUI.

Worked well. Not quite the same as this, but that’s what this reminds me of.