I expect one of the devs will chip in and give your the answer from team Scaler, but the Midi Manufacturers Association have published detailed information about what happens when the world of MIDI 1 collides with the world of MIDI 2.
A key part of the upgrade spec is to make interworking transparent. This is done by something called MIDI-CI, or Capability Inquiry, where (as far as I can tell as a non-expert ignoramus) a V2 device will enquire of whatever is at the other end of the wire to figure out what to interchange. If you check at www.midi.org, and d/l document M2-101-UM called “MIDI Capability Inquiry (MIDI-CI)” (and of course you can download the MIDI 2 spec from there). These docs may answer your generic questions about hardware. Scaler, AFAIK, is MIDI 1 only.