[not sure if this is uptodate, i did it in the past (RELENG_5/6) for
my mp3 player]
I would start with a DA_Q_NO_SYNC_CACHE quirk.
also, to apply quirks without rebuilding a kernel you can use the recent
'kldpatch' port -- the man page contains an example for umass.ko
that should cover your case (by changing the numbers of course)