I’m experimenting with Redux in REAPER, and it seems as if I place a Program Change at the same MIDI position as a note, then Redux will start playing the note and then change the program.
Apparently PC events are supposed to be processed before MIDI notes… I’ve tested other plugins that behave that way. This way I can set a PC at 1.1.00 and a note at 1.1.00 and the PC will be applied to that specific note.