Music App large library

Just got a new Mac Mini with the M1 chip. It will be getting a data transfer from a 2013 MacBook Pro that has been used primarily for a music library. There are currently over 1M songs in the iTunes lirbary (this is for work)(all songs double backed up on external drives). We tried using Music on another laptop to get a feel for it before switching the main one over from iTunes. Apple finally made a couple of changes to Music (allowing artwork when you are viewing songs and fixing other small things) and we tried it with the main library.

The library has been trying find the artwork for 5 days now and has gotten less than 10%. Not really a big deal as long as it keeps working on it. A lot of the music is not in the Apple store, so clicking on Get Artwork is not going to be helpful. This morning it said that all available RAM had been used and forced a restart. Then Music said "The library “Music Library” does not appear to be a valid music library. Music has created a new music library and renamed the damaged library to “Music Library (Damaged)”" When we started Music for the first time we held the shift key and pointed it to the iTunes.itl file.

We're beyond frustrated here. We're now back to using Retroactive and iTunes on the laptop. We'll be syncing the Mac Mini this weekend. Any suggestions on what to do? Not having artwork is not an option. Is there a work around? I've spent two days reading all of the posts on here and no one seems to have a good solution. I even tried downloading some of the apps people put on Github to deal with it and couldn't get them to work on the "other laptop" so won't try them on the main music one.

Looking for any help you guys have. Thanks!