Regarding the addition of the lcd, it could be stacked above the pi board but the board is faced the wrong way for that. If the pins needed were added to the OSPi board offset from the edge of the RPi board then with long headers it could be easily mounted. A taller case would probably be needed but I would think it would fit into the higher case that has been noted other places (would need the user to cut the holes). I have sketched the stacking if my description isn’t clear. I could also add a board between the RPi and OSPi to bring the header to the side with no changes to the Pi or OSPi but the height increases(top sketch).
I take it the note on hosting the webUI on the RPi is in regard to no network connection. I realize I wouldn’t get automatic time setting/sync so the time would drift a bit and have to be set manually. The battery should handle power outages though. Any other limitations with no network connection?
For some reason the jpg file doesn’t seem to show up when I post.