Nice work as usual, clvn! I'm a little late to the party, but I've finally taken a look on your converter. Attached is my updates with parsing of tempo, controllers, pitch and some meta events, corrected parsing of variable-length values (used for delta and note duration), and writing of track names.
The remaining unhandled codes used by the music files looks like loop markers.
I tried to read additional instrument settings from MTSKIDMS.VCE (commented out in the attached source), but the MT-32 patches just sounds awful, even on my 90s Roland GM module...