Keep in mind both LibreWolf and Mull are very slow because LibreWolf disabled WebGL, enabling higher privacy features, and Mull disabled JIT, a massive performance hit.

This is for people who don’t know then blaming Firefox being slow, LibreWolf and Mull are slower version of Firefox, just that.

Can this poll be considered official ? I clicked the link and it looks like a Twitter poll or something.

Yep, waiting for this feature so userChrome.js cook-ers can turn it into Tree Style Tab Group like Sidebery, with this config exposed it would be surprised if it takes long for us users to try the test version.

Smart Tab Group is pretty hype too.