This ACA500 sounds very flexible.
I wonder if it can be used with other Franken-Amiga expansions like
a Slingshot Pro:
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=1395which enables a zorro II slot, on the side expansion slot, with a side expansion slot pass-through
This would allow a zorro II card in addition to the ACA 500, "in theory"
or
the 86pin Adapter
http://www.bigbookofamigahardware.com/bboah/product.aspx?id=709This is an 86-pin side expansion slot doubler.
In theory one could use the ACA500 with a side slot SCSI controller "like the GVP HD8+"
or an A570
My guess is the slingshot might work, but my guess is that the ACA500 and something like an A570 would interfere on the 86 pin bus.