@zzrwood and @lelek
no need to use anything more than my DAW!
I just connected my M-Audio Keystation MINI 32 + Alesis Q49, and the system, Ableton Live 11 included, sees both keyboards
I tested HaNonB701 (simil-Hammond) that has a keyboard splitter, and I was able to use both keyboards with the Hammond: the small one for chords and the bigger for melodies, like I was Rick Wakeman… 
Well, not just the same style, but a lot of fun anyway
Then I tried 2 instruments, EZKeys and HaNonB701, with 2 Scaler’s instances:
Scaler 1 feeding a series of chords in loop, and Scaler 2 muted and in Key Lock to play solos
BOMBASTIC!