How to customize Firefox hotkeys?

Question

I have enjoyed using the Command/Ctrl+J hotkey to launch the Download manager in Firefox, on both macOS and Windows. Now that I am using Ubuntu more often, I noticed that Firefox unfortunately uses a different hotkey mapping, requiring Ctrl+Shift+Y to launch the Download manager. In Linux, Ctrl+J instead focuses on the search bar / address bar, which is already mapped to Ctrl+K and often Ctrl+L anyway.

How can I fix my Firefox configuration so that Ctrl+J launches the Download manager on Linux, instead of focusing the search bar? I mean, I could recompile Firefox, but I would like to know if there is a more accessible way to do this, such as the Preferences editor, or the about:config page, or some browser extension for this.

I suppose I could also capture the Ctrl+J sequence at the keyboard level and have that type out Ctrl+Shift+Y, but I would only want that performed specifically for the Firefox application, and I'd prefer not to muck with how my keyboard works, just customize the Firefox hotkeys.

I already tried the "Shortkeys" extension, but it is able to remap very few features, none of which include the Download manager or search bar focus hotkeys. That extension is sadly limited by the Firefox extension API, which does not appear to expose remapping of these features.

Is there a better way?

Answer 1

Unfortunately there isn't. You already mentioned almost all of the options you have.

The only options you didn't mention are hotkey reconfiguration on the system application/Window Manager/OS level.

The only practical suggestion I can provide you with, has to do with the application level. You may want to take a look at AutoKey, a desktop automation utility for Linux and X11. Use it to make one key sequence to trigger another. It is a clunky solution and I have to warn you that Autokey is often not working as intended and is much more inferior in comparison to the Windows' AutoHotKey. But hey, you can try - maybe it will work fine in your particular case!