Hello timothy.duncan,

The only thing that I could find that covers this keyboard shortcut, is this (older) thread :

http://forums.mozillazine.org/viewtopic.php?f=38&t=3025123

Any good ?

I'm also having this issue, but I'd like to disable the command-K keyboard shortcut to open a search in the address bar in Firefox for Mac because it interferes with the ability to use command-K to add a hyperlink to selected text in a Google Doc. The thread linked above suggests the Durando Keyconfig add-on, but the link to it is broken, and searching for "durando keyconfig" in firefox add-ons gives only one result which is not that add-on.

Web pages should be able to intercept most keyboard shortcuts. For example, my test page here -- but I haven't tested with Mac:

https://www.jeffersonscher.com/res/keyvents.html

You could look at Shortkeys. I don't know whether it has the ability to pass the key combination through to the page versus just throwing it away.

https://addons.mozilla.org/firefox/addon/shortkeys/

If you try it out, let us know how it goes.