Hello, I have an AUDYA 4, I have the same questions than you,
but I think that the patterns called Guitar Bank-1 or Guitar Bank-2 (MIDI GUITARS) are stored in ROM, or in a RAM that load when keyboard starts, isn't possible to make USER guitar.

Audio Live Guitars it's the same, the user can't make this files, only KETRON.

It's possible to exceed the limit of 4 gtr files loaded in RAM?.
Do you know this:

https://www.ketron.it/prodotti/306-espansioni/espansione-ram-128mb