What I'm using... Always a WIP
make all
My hyper key is set up using hidutil. In order to have the mapping persist reboots, we need to load the com.local.KeyRemapping.plist service file (generated with this tool).
# move the file into place
copy ./com.local.KeyRemapping.plist ~/Library/LaunchAgents/com.local.KeyRemapping.plist
# load and start the service
launchctl load ~/Library/LaunchAgents/com.local.KeyRemapping.plist
launchctl start com.local.KeyRemapping