Rated 5 out of 5 stars

Thank you for bringing this back.
I'm sure that updating it wasn't too fun.

My only issue with it is that the menu bar text is very light. It kind of looks disabled.

I have 48x48px, and 64x64px sized Tab Groups icons (and code) if you're interested in the XPI at the following.

I may still have the SVG if you'd like that instead.

Thanks for the link, I may consider it in future. If I do, however, it'll likely be implemented after the menu bar fix (which I'm still trying to diagnose) and possibly doorhanger notifications. KRL uses 48x48 and 32x32 icons, so it'd be preferable if you had the SVG icons available, so I can get them just that bit smaller than your raster images.