It works well but I had trouble finding this extension because I was searching for youtube, not YT. Nobody knows what YT is. Consider changing the name to Youtube Miniplayer Blocker or similar. I found you can do the same thing as this extension just by blocking the address www.youtube.com##ytd-miniplayer

It works perfectly fine. YT are fckng morons who made me to install 5+ extensions to make it less annoying since ~2018

Thank you for this, stupid mini player was driving me crazy!!!

works thx