if you want to put something on GH i’d be happy to contribute, though i’m travelling without grid or much extra hardware until mid-january.
what i’m thinking is that another kind of “elegance” can be achieved by adding a small scripting layer (lua) to the adapter. using a 128-button grid as a 1:1 midi controller is minimally useful by itself. and requires software to manage state and mappings. something like isonome has a very small footprint, doesn’t require complicated timing stuff, and makes the grid+dongle into a simple but flexible controller.
the reason i think this is “elegant” is it takes the functionality out of the iOS (or whatever) software, so you have a playing surface that behaves the same regardless of what you plug it into. a “passthrough” setting can still be used for more complicated UIs implemented host-side.
MIDI issues: whats the best way to map multiple keys with the same note number? different channels? can audulus handle multiple channels? &c.