Okay, so, in the rpm spec, you can patch wg-quick.bash before the make install.

sed -n -i -e '/^cmd_usage()/r path/to/hatchet.bash' -e 1x -e
'2,${x;p}' -e '${x;p}' path/to/src/tools/wg-quick.bash

This is using the attached hatchet.bash file.