Perhaps try tdewolff/minify?

[tdewolff]

I know I'm the author of https://github.com/tdewolff/minify, but while using MkDocs I wondered what this plugin was using. It came out as the fastest minifier by far (see https://github.com/privatenumber/minification-benchmarks) and may be useful if you want to compress more quickly. Just an idea, if there is no need you may close this issue of course :-)