I believe if you edit s_midi.c and change:
if (midi_outqueue[midi_outtail].q_time = midirealtime
 to
if (1)
 and
if (midi_inqueue[midi_intail].q_time = logicaltime)
 also to
if (1)
 
 that will make it fast-as-possible.  The queueing code should probably
 be surrounded by an ifdef to make this easier (perhaps someday...)