Ok, I’m sorry to keep wasting bandwidth on half solving my own problems, but it’s been a learning experience at least! I just found that my problem with the mosaic not expanding as I add frames is that I had chosen a mode of “reference” in 6) Integrate. Changing that to Full solved this problem as well as the majority of the registration problems.
I’ve successfully integrated 4 panels. I’ll try to do more and report back later.
Sorry again for all the unnecessary comments.