Yeah i know about “ no latency “ doesn’t exist , i was trying to say for very reduced latency
and Midi learn is a feature of the plug ins inside a music production Digital work stations that sets ready the plug in to “ hear or engage or attach “ the plug in to the Analog Fader external controller ; so i’m telling that the external controller when plugged can be instant ready/able to recognize the midi learning feature from Ableton , like much other controllers do it
I know that for a PC/laptop to recognise an Arduino as a native MIDI device, only certain models of Arduino will work. Arduino Pro Micro or Leonardo, for example, and some others. These models of Arduino have "native USB" not a separate USB-serial chip.