The main protocols for me are CAN and ISO. I do a lot of manual switching back and forth on my old slow serial ELM. I have a CAN/ISO Mongoose as well - that may not have been made obvious in this thread.
Is there any chance a J2534 'shim' may be on it's way for the OBDPro? It would obviously have to do a lot of fudging. I know you've touched on it as a future possibility in the past. No harm in asking again.