Never seen or heard of this being done (successfully) before. Very interesting.
The ACA630 clips over the 68K chip, so it wouldn't be affected by the status of the trapdoor connector. Whether the 010 throws it off is another matter - my guess would be that it doesn't, since the 010 is pin compatible.
You'd probably seen to ask Jens Schoenfeld directly whether the clockport and other goodies on an A604 would work in such a machine.
Got any photos of the board? I'd love to see what it looks like.