MIDI-in during render

I have a funny configuration for a song: Renoise is sending MIDI notes to Max/MSP, which processes them and sends MIDI back (procedurally altered note-ons and CC data). During playback, the MIDI returns play Renoise’s samples just fine.

But Renoise appears not to listen to MIDI-in during render, even in realtime mode. I can see that the MIDI is being sent out to Max, but no audio is appearing on the meters and the output file is silent.

Is there any way around this without routing audio to another DAW via JACK?

Did you tried setting the Ext.Midi Mode to “Line-in return” in the instrument Ext.Midi properties?
Aha sorry, i notice that you are sending back midi data. I believe Renoise is ignoring midi input during rendering, you might want to try to connect the midi input source directly to the instrument, but with rendering only audio feedback is expected (and recorded if the above suggestion was checked).
Or use plugins like Voxengo Recorder (which do the output rendering job fine in realtime).

It’s a little gnarly because Max is taking in one channel and sending it back to Renoise on three separate channels so that each can get its own instrument & track (for DSP/mixer purposes).

As a stopgap I’m just playing the song and recording in Reaper, which works fine. But I wonder why Renoise doesn’t accept MIDI messages during rendering?

Thanks as always Mr. Voo(ooo)is.