That sounds suspiciously like a number placed in a style sheet. Have you checked in the directory for your Firefox profile?

I already forgot the details, but I tried some solutions like this I could google up. Yes, I remember changing some numbers in some files in the profiles. Nothing worked. Apparently these were only meant to work with older versions.

>I already enabled URL display so it already is two-line effectively but I feel like probably making both parts (the title and the URL) two-line each.

So apart from having URL + Title shown at the same time, I take it you mean to reserve two lines for those to have some room to wrap? I'll add a note to try it as a setting.

I documented unlocking the width of the sidebar in Firefox here: https://dev.to/semanticdata/unlock-the-sidebar-width-in-fire...

This worked (with Firefox 118.0b2). Thank you very much. I already had almost proper userChrome.css there I apparently created previously but I never knew sidebar should be replaced with sidebar-box.