Plain old Midi files of course can't do micrononal materiel. Hence iannix would need to adhere to some specification on how to send such information.
MPE with pitchbend like I proved that PianoTeq does accept is one such specification, which indeed is explicitely covered by the (new) Midi standard.
Another could be "compress semitone in the note events by a factor of 10" or whatever and hence rather "propriety".
Of course there could be lots of other ways to code microtonal material - including the "realtime tuning" by Sysex messages (which is very inefficient for your task, but seemingly also some kind of standard).
So you need to find out what iannix in fact is doing.
Unfortunately in the rpp files you sent me there are no recorded midi data (no Midi item exists in the track) .
-Michael