i have a question and maybe feature request for midi-cat: i played around a bit with midi-cat and an akai apc key 25 controller - it has many buttons and i managed to map them nicely via midi-cat (a big thanks for all those amazing modules btw.) but the feedback to the lights of the buttons is not perfect yet … if i press any of the buttons it sends a note on channel 1 with velocity 127 and midi-cat is sending this note back which results in a green light on the button
the buttons on this controller (and i guess all other akai controllers too maybe) can be lit depending on the velocity value of a note on event being sent back: 0 = off, 1 = green, 2 = green blinking, 3 = red, 4 = red blinking, 5 = yellow, 6 = yellow blinking, all remainings = green …
would it be possible to add an option to either midi-cat - or even better: to each mapping - to choose a defined velocity value to send back to the device instead of returning the received one back to it in toggle mode on every “toggle off”? as a bonus this configurable velocity value could also be sent back with a “note on” instead of “note off” command in momentary mode when you receive the note off event on the input
with this it would be possible to easily get very good visual feedback on the buttons about their state … if that configurable velocity could be configured on a per mapping basis, one could even give different buttons different colors
it would be really really nice if this could be somehow added to midi-cat 
best wishes and thanks once more for your modules - hexdump
update: i just rethought about the multiple colour mode - this would actually require two custom velocities to be configurable: one (something like “light in a sepcial color on” - 1…6 for the akai controller depending on color) which is sent with the “toggle on” in toggle mode and with the “note on” in momentary mode and one (something like “light off” - 0 for the akai for light off) for the “toggle off” in toggle mode and for the “note on” sent instead of “note off” in momentary mode … so maybe as a start a green only mode should be enough and this would only require this configurable velocity value to be sent back at toggle off instead of the received velocity and this could even be configured globally for all mappings of a midi-cat module, so no really big required change to midi-cat i guess
update 2: it looks like my proposal would even work on novation launch xyz controllers - they only have to be put into a special control mode first: https://www.partsnotincluded.com/how-to-control-the-leds-on-a-novation-launchkey-mini-ii/