There are other tab behvaiors that TabMixPlus offers including going to the last used tab on close, open in foreground tab in the context menu for links, scroll wheel to cycle through tabs, and some other things I take for granted and then get disoriented when I use FF57.

Without those, it's painful. I will stick to the older Firefox (or maybe an alternative like Waterfox) until it becomes impossible to use new sites with it, or if somebody (myself included) reimplements these features in a way compatible with FF57.

> scroll wheel to cycle through tabs,

This is the single most infuriating thing for me and I just don't understand why this is not a standard option, especially since it works perfectly fine by default on Chrome!

Probably because it's used for scrolling the tab strip when the amount of tabs is so high that their width stops shrinking and further overflowing tabs are clipped from the strip area.

Relatedly, if you use Tree Style Tab there's an extending extension that adds proper mouse wheel scrolling: https://addons.mozilla.org/en-US/firefox/addon/tree-style-ta...

I'm using some modification of that get to get multi-row tabs -- not ideal but it works.

I'm no longer even sure which is the final version of it. There are some unfortunate quirks with it.

Did you manage to enable scrolling of the mouse wheel to switch tabs?

No. :(

I also started looking into using CSS grids to make the tab sizing better but that created it's own problems. I need to spend more time working on it.