I used Keyboard Maestro to create shortcuts for volume up/down, brightness up/down, play/pause, previous/next, and Mission Control.
I already had Caps Lock mapped to Escape with Karabiner-Elements.
Probably be more useful once more apps take advantage of it. So far only a few non-Apple apps I use take advantage of it. I do hope Slack takes advantage soon.
I have mapped Control to Caps Lock, do you have any trouble reaching control? I find it very awkward with the Fn key there ...