Slow Export + Add to Catalog

I am always astonished by how awful Lightroom is, and how it makes my life as unproductive as possible.

I have a very fast computer (Mac Studio) and reasonably fast disk (RAID 5 spinning disks) and the latest version of LR Classic. I am keeping sets of photos each in a different Lightroom database, as that is the easiest way to organize them.

Today I wanted to export every photo in a database (about 2,200 photos) in two different resolutions (full size and 1200x800). I stupidly set "add to this database" in my export settings. Exporting the photos took only a few minutes. But...

Now Lightroom is adding the photos to the database at the rate of 30-40/minute! (that's about 1 hour of processing!) I'd like to get on to the next database and export from that one, but I can't, because I can't quit Lightroom. I don't want to force quit because of the chance of corrupting the database.

I hate Lightroom Classic more than any other program that I am forced to use.