As a first python project I made this CLI script. It properly removes pictures, oversized padding and id3 tags from flac files.
Requirements:
python 3.5 +
mutagen library (pip install mutagen)
Features:
much faster than metaflac
works on single files and folders (also checks subfolders)
works independent of file extension
accepts multiple input paths
Options:
check-only mode for diagnostics
save pictures to disk (no dupes will be saved)
customisable padding size
don't remove pictures
don't remove id3 tags
silent mode