for sure. I don't know if people are doing it because it's better, or because they're trying to justify having dual trackballs.
I've seen people use one trackball for normal mouse type usage, and the other for scrolling.
I second this. I also prefer ZMK and use it on my wired boards whenever possible.
There are some low profile tripod stands. the manfrotto MP3-BK is nice, but pretty expensive. There are also a bunch of "Z Tripods" that get used a lot.
A 3d printed case for tenting is definitely an option, but it can take a while to find the right tenting angle so be prepared to possible print multiple variations.
MJF printed ChicagoSteno.