Even with generous storage space, I can only justify keeping maybe one copy of the album in FLAC. And then it comes down to which version will I archive as FLAC: the original pressing? The recent remaster? The "collector's edition"? The ridiculously hard-to-find Japanese SACD pressing?

All of them. Preferably with a 600dpi scan of each artwork.

Flac is meant for archival purposes. You transcode to opus for listening.

Storage is cheap. I prefer FLAC if I have the space to spare. Hey, look, another backup of my music collection!

20k?? Lol! Those are rookie numbers. That’s like the most essential albums I’m carrying around on my phone for daily use...