TIL that chrome has a really cool JS/CSS coverage analysis for dev tools, for which FireFox has no equivalent! This is the first time I've seen an actual deficiency in FireFox for webdev.
https://developer.chrome.com/docs/devtools/coverage/
https://stackoverflow.com/questions/64605981/alternative-for-chromes-coverage-in-firefox
But whatever happened to yesteryears https://developer.mozilla.org.cach3.com/en-US/docs/Tools/CSS_Coverage ??