Chrome, FF, others? lock extensions to the upper-right toolbar. Customization allows altering their order, but they're still stuck in that corner. Part of my site-ripping for my high-volume reading sites is to minimize cursor movement, both for speed and ergonomics. Yet, if an extension doesn't offer a control in the context menu I have to go all the way back to top-right.
PITA.
Since 2017-ish FF has really increased the lockdown of extensions/addons. There used to be (apparently popular) addons to allow copies of addons in a custom bottom auxiliary toolbar --now removed.
The only flexibility that remains is in the context menu but it is up to the developer to add that option. Luckily for my needs, I just found one to replace the no-context version I had been using since moving to FF.
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The addon I use constantly is covered here:
seo/tracking: I'm flooding FF history files
http://th3core.com/talk/traffic/seotracking-i'm-flooding-ff-history-files/msg80023/#msg80023
Besides obfuscating my history files, I also use it to 'white-out' previously visited links on a page so I only see new-to-me headlines.
>white-out
For example, Mojeek News, reddit, NewsNow, others rotate their posts so they are good candidates for revisiting during the day for updated content. But I want to avoid spending time looking through olds posts I've already dismissed.
Here's what Mojeek News looks like on a revisit:
Holy crap! Whatever happened to easy-ish context menu modifications in FF? I know I used to modify userchrome long ago but this is now a PITA.