Instead of generating the interface configuration commands by hand, make use of vyos.ifconfig like it is done in bridge, loopback, dummy and soon bonding interface.
While doing this transition it should also be made use of the VYOS_TAGNODE_VALUE environment variable so the interface-wireguard.py script is only run for the specified tag node and not on all tag nodes.
This results in only the interface which had changes in the CLI will be changed. All other WireGuard interfaces are not processed.