I've run BA23's with either an RX50 or TK50,
and a pair of piggy-backed RD32's. It seemed to work well.
I had soldered a pair of 2.2K (?) resistors
onto the back of the 4-button panel to force the 2nd drive
"ready" and "write enabled" full-time.
I may have the details on that particular modification
tucked away in my documentation somewhere.
I also worked up instructions a while back to construct
a ribbon cable to go from an RQDXn controller directly to
an RX50 or RX33.
I should be able to dig that up as well, if anyone is interested.
T