First of all, have you seen the “classical editor toolbox”? If not, check that out:
If you’re adding Disc IDs, don’t bother with this, they will be added for you.
I know it’s generally better to reuse existing recordings (when you know they’re right), but if you want to cut down on time used, drop this step as well and consider using @jesus2099’s “mb. MASS MERGE RECORDINGS” userscript to merge recordings en masse after the release has been added:
In the same vein, what I have sometimes done for multi-CD releases is to add each medium as its own release using a CD TOC/Disc ID lookup (from Picard, isrcsubmit.py, or other means) and then merge all the releases together at the end. If you know the full track listing though, it will probably be quicker/easier to use the track parser to populate the release and then add Disc IDs afterwards.