Thanks LDT & Machina.
That was the route I took, but I’m got my second MTP AV, which has failed (just like the 1st – blank / malfunctioning screen & no midi routing going on), so my impression of them isn’t too great at present !
I was gonna get a Unitor, but I think they’re serial, which also means the software’s old and probably not support on OSx.
Maybe I’ll just send the MTP back and try again – 3rd time lucky !
At least I’m going down the right approach – as you guys have confirmed !