There's no possible 'workaround' for the CPU slot's missing INT2 signal that could be done on the accelerator. It must be added on the mainboard.
The DMAC controls the flow of data to and from the WD33C93 while the latter controls the SCSI bus. The DMAC is for the WD33C93 pretty much what Agnus is for Denise, if that makes any sense.
