I imagine one could replace the hardware with something else to drive the display portion. It'd take knowledge and a soldering iron, but I'm sure it's doable.
Probably they have some sort of sensor behind the lower screen that can tell if it's covered. I wonder how sophisticated that is. Perhaps, rather than covering it completely, it could be obscured behind a crystal pattern plastic sheet, like is used for privacy. It would still let the light through, but it would just be an incoherent light pattern. Build a box to enclose the bottom half, and hold the sheet out a few inches in front of the panel.
EDIT: The correct way to deal with it is to disable the backlight on the bottom display. Found a reddit post about it. It's cheap and easy enough to do if you have a soldering iron.
EDIT 2: Apparently it does not have a way to detect if the bottom screen is blocked. Fools. Just build a box around the bottom part, and you're done. https://www.youtube.com/shorts/qD-jaukv85U
