Okay, it seems like FullPageOS kind of nearly fixed my issues with setting up a Raspberry Pi Touch Display 2 in kiosk mode. It's very opinionated, and need a few tweaks, but it's "less bad" than setting up from scratch. Still need to play around with it more to have a final opinion.
Now, here's the biggest advantage of that option: it's built buy @guysoft, the same person who builds OctoPi. So, even though right now it seems to be in a bad/broken development cycle, it's still an interesting project to keep an eye on.