MacOS – make a custom keyboard shortcut available to all users

This is a known “bug” which I don’t know if Apple will ever consider a bug.

The problem is that the list of browsers is generated “dynamically” each time you click on it (or at least the 1st time after Safari has been launched); the reasoning behind this is that different users will have a different set of browsers, so the list cannot be hardcoded. So given the above, the shortcut fails to work until the list has been “generated” by Safari. This occurs when you display the menu.

A possible solution would be to use Automator and create a service that opens the current safari page onto Chrome. But that’s beyond the scope of this answer.

TLDR version: There’s nothing you can do other than file a bug report at Apple if you want to stick with the same shortcut technique. Alternatives involve Automator.

The default input source is set in ~/Library/Preferences/ByHost/com.apple.HIToolbox.*.plist (where * is system_profiler | grep 'Hardware UUID').

You could either copy the file to other acccounts: sudo cp ~/Library/Preferences/ByHost/com.apple.HIToolbox.*.plist ~/Users/username/Library/Preferences/ByHost/.

Or add it to the User Template directory so that it will be included by default on new accounts: d=/System/Library/User\ Template/English.lproj/Library/Preferences/ByHost; sudo mkdir -p "$d"; sudo cp ~/Library/Preferences/ByHost/com.apple.HIToolbox.*.plist "$d".

Note that the UUID will have to be changed if the file is copied to another computer.

You can view or edit the property list in a text editor by converting it from binary to XML: f=~/Library/Preferences/ByHost/com.apple.HIToolbox.*.plist; plutil -convert xml1 $f; open $f -a TextEdit.