I've read in the data list, specifically the midi data table. The montage will respond to a gm system on SysEx message, is this the same thing as selecting Performance -> Category search -> Init -> multi/gm from the front panel?

That is exactly what that means. However, that is just about as far as the compatibility goes. It places 129 sounds at your service for GM use.... the 128 Normal GM instruments (16 Categories, 8 sounds in each) MSB 0, LSB 0, PC #1-128; and at MSB 127, LSB 0 PC #1 the GM Kit.

The MONTAGE does not do NRPN, nor do offsets to Filter, Envelope, necessarily work with 100% accuracy to a proper/official GM module. It is assumed the customer here want to RE-WORK Standard MIDI Files in GM or XG format with the tools found in the MONTAGE ENGINE. You may find files where the author used the Filter to Brighten the sound (due to the lack of EQ in the GM spec)... that this sends the MONTAGE sound into howling madness - as the very deep Filters of the MONTAGE tend to do a bit more Filtering (Cutoff/Resonance) than those found in the typical GM-spec'd unit.

The envelopes are also more complex and you may not get the same results as in a GM module. So it is a pseudo-GM Set, expect to do some tweaking -- the Reset response will get you the right instrument... then you can replace it with any other MONTAGE sound appropriate for the instrument part.

@Bad Mister. Excellent! The resetting aspect was what I was after, I was fully aware it wasn't going to respond the same way as a gm module... I've already got enough of those as it is! 🙂