would it be possible (without changing the code), to suppress the rtprinf outputs in default_libpd_render.cpp? My connected MIDI devices send system events every n ms and Bela is complaining (and me too, because I can't catch the messages I need). Setting int gMidiVerbose = 0; would be easy enough.

if you want to avoid printing to the console of MIDI messages you can do

[loadbang]
|
[verbose 0]
|
[s bela_setMidi]