Ah nice! Well just installed and I will give it a try then. Would really like to see Firefox adopt it too. I've looked into addons for Firefox to accomplish it, but none of them are as good as Edge (and now Brave's) implementation.
If that does a list of tabs to the side try the addon "tree style tabs". The only downside is that because it is an add on you need to hide the top tabs manually with css. Been using it for years. Love it.
The functionality of auto hiding the tabs when not in use and being visible when hovered over is the functionality I need. I might be lazy, but it's what I am looking for. I've tried all the ones I could for Firefox and none replicated that functionality sadly. Outside of that, I also want to be able to create web apps, which Firefox also did not support the last I checked.