So, the action 41144 is called "FX: Set
MIDI learn for last touched FX parameter" and it's only accepts, though, as the name says, but it calls the following window, with title bar "MIDI/
OSC Learn", which is confusing in a way "Why doesn't it accept incoming OSC.
I think that devs might've forgot about adding OSC functionality to this action, when OSC was first introduced to Reaper. And there's no similar built-in action in Reaper for
OSC learn.
So, is it possible to rename this action to "FX: Set
MIDI/OSC learn for last touched FX parameter" and allow it to map OSC commands?
And, as I've already posted before, when this action is mapped to the keyboard hotkey or activated from action list, osc mapping becomes possible.