Hmm, I see LZ77, PPM and entropy coding in the description, and obviously Burrows-Wheeler. Has anyone tried doing zstd at the end instead of LZ77 and entropy c

Hmm, I see LZ77, PPM and entropy coding in the description, and obviously Burrows-Wheeler. Has anyone tried doing zstd at the end instead of LZ77 and entropy coding? Does the idea even make sense? (I'm a layman)