Convert FLACs (or other format) to OPUS 96k (lossy!) for space savings
Requires ffmpeg in %PATH%
ls -Recurse *.flac | % -Parallel { ffmpeg -i $_.FullName -hide_banner -loglevel warning -y -c:a libopus -b:a 96K -af aresample=resampler=soxr -ar 48000 -map_metadata 0 -map_metadata 0:s:0 -id3v2_version 3 -vn ($_.Directory.FullName + "\" + $_.BaseName + ".opus")}
You will have to manually remove the original files.