shnsplit
shnsplit utility⚑
Split multi-track FLAC to single tracks⚑
You need the cue file for the times and metadata. Then:
shnsplit -f file.cue -t %n-%t -o flac file.flac
(https://unix.stackexchange.com/questions/10251/how-do-i-split-a-flac-with-a-cue)