Hi and welcome to the Bome community!
Well there is a piece of the puzzle I do not understand, so I will need to ask a few question first.
In your Luminosus software, is there any way to pick which MIDI device your want to use for input or is it opening all available MIDI ports?
If you can select a single input port, then we should be able to use Bome MIDI Translator to merge the inputs from both controllers and send to one virtual MIDI port while translating the input from one of the controllers so that from a Luminosus point of view, the two controllers will appear as one controller instead of 2.
So the picture would look like this
APC20(1) ------> Bome MIDI Translator Pro (MIDI THRU) → Bome Virtual Port 1
APC20(2) ------->Bome MIDI Translator Pro (Translated) → Bome Virtual Port 1
Then set up Luminosus to look only and Bome Virtual Port 1 (which might be seen by Luminosus as “BMT 1”.
Steve Caldwell
Bome Customer Care
Also available for paid consulting services: bome@sniz.biz