And according to this document, 2-18, one of the MacCon cards (I seem to recall that I have one) had a removeable AUI daughter card on the connections board, making it possible to replace it with a video port from a card such as one of these. Those ribbons did come in handy....

Now all I have to do is see for sure if a right-angle adapter can be fashioned by cannibalizing one of my spare IIsi nubus adapters. If so, then it seems that an Asante MacCon + piggy-backed SE/30 PDS video card mounted vertically in an SE/30 should be eminently possible, even for the electronically-challenged.