Just a quick note about port names.
Normally, Montage, MODX and Montage M will advertise MIDI port names ending in a number to your computer. In each case, port 1 is the one that is used for general USB MIDI communication, and it is that port that should be used with KDx.
I have encountered very rare instances where Montage M has provided names like "MONTAGE M Main". In these cases, KDx will not auto-detect your synth, buy you can use the manual config tools to connect to your synth.