Yes, you can get the new faces, but it's a pain. Yes you are correct about the return value. Yes, it would be nice to have had the newly created faces returned instead of nil.

To get the new faces, you have to take an inventory (make an array) of the current set of faces in active_entities before the pushpull. After the pushpull, you take a second inventory, and subtract the first inventory from the second. The remaining faces are the new ones. Of the remaining new faces, the one with the same normal as the face that was pushpulled is the parallel face if you need that one specifically.

I've posted the code to do this at least twice. Try a search if the above eludes you.

Todd