@AlAl, Thank you!
@KentuckyKen, maybe well below $1k, this tool is getting low enough to just buy one individually. I'm getting pretty close myself, will look into the 808 a bit more, might just order one.
The biggest problems I see with my original round-robin idea is not only logistics (as you noted), but what happens if it's damaged/lost in shipping, or say a member accidentally drops it on a concrete floor and the display cracks, or it otherwise breaks. Anyway, at below $1,000, still a luxury item for many, but I think I'm in for one.
The manuals are here:
https://support.autel.com/support/solutions/folders/8000078944
(the MK808 is lower right, MS906 upper left)
Some of the BT, TS differences appear to be a hardwired cable or a Bluetooth plugin at the OBDII connector, not entirely sure yet.
I guess the only thing I want to do first is to compare AIAI's instruction pages to some of the manuals to be sure that those features are available. I have a difficult time seeing the differences between the various model numbers.