it worked well for me, copying news-text and posting links as I needed them. While I wait for your new version for quantum (fingers crossed), I have found that I can post text into a translation service called Deepl which removes, happily, all formatting.
"Copy PlainText" has always been compatible with Firefox Quantum. I wrote it for that reason. Is it possible that you are referring to "Copy Plain Text" (extra space between plain & text) which is a different add-on?
