Firefox vs Chrome: how to open new tabs in foreground or background with same meta keys? The Request

How can I make the same meta keys between Firefox and Chrome do the same thing?

In my macOS, currently in my environment (&lt;click&gt; = "mouse left click on weblink"), the following "open new weblink in new tab" keyboard behavior is inconsistent between Firefox and Chrome.

Chrome


open new-web-page tab in foreground: cmd-shift-&lt;click&gt;
open new-web-page tab in background: cmd-&lt;click&gt;


Firefox


open new-web-page tab in foreground: cmd-&lt;click&gt;
open new-web-page tab in background: cmd-shift-&lt;click&gt;



It matters less which keyboard-shorcut-plus-click does which thing (although I'd prefer the cmd-&lt;click&gt; opens in _background); I at least want the behavior to be consistent between these 2 web-browsing apps.

My current versions

macos: 10.14.6
firefox: 76.0.1 (64-bit)
chrome: Version 81.0.4044.92 (Official Build) (64-bit)


Failed (thus far) solutions

I've thus far been unable to get the following solutions to help/work:


https://github.com/mikecrittenden/shortkeys/wiki/How-To-Use-Shortkeys
https://superuser.com/a/1260437/98033
Employing the following Firefox preferences settings achieved what I wanted. In particular: the annotation highlights the setting I unchecked that made things work on my system.