Very good game plan.My moving old rock and sand plan didn't survive 1st contact.
At some point I decided 2 things:
1. I wanted to take my time for the aquascaping and not just go with stacking rocks.
2. I was not confident in a wholesale move from a 34 to 108 gal tank wouldn't have casualties.
So I decided to just go fresh and new and transition things slowly.
The new tank is cycled and refugium is up and running. I'll start transitioning after the new year.
Have you tested the new aquarium for phosphate? Will you try and match most of your parameters in old and new tanks before you begin transferring the corals?