I don't know if anyone else actually uses this, but I bolted ZX0 decompression support into bin2cas.pl (uses the "salvador" external tool for compression). Achieves better compression than dzip, but needs a larger decompressor. With thanks to Doug Masten for writing a 6809 unpacker (slightly optimised for space to get it into a filename block along with other features).
http://www.6809.org.uk/dragon/#castools
Salvador: https://github.com/emmanuel-marty/salvador
And here's Doug's repo: https://github.com/dougmasten/zx0-6x09
bin2cas.pl 3.14
Re: bin2cas.pl 3.14
I still use this