I had previously come across an in-tree WireGuard extension for Flannel, https://github.com/coreos/flannel/blob/master/dist/extension-wireguard https://github.c

I had previously come across an in-tree WireGuard extension for Flannel, https://github.com/coreos/flannel/blob/master/dist/extension-wireguard https://github.com/coreos/flannel/blob/master/dist/extension.... However, Flannel's WireGuard extension looked way too experimental, and unmaintained. I realise it is also early days for Gravitational Wormhole, but Gravitational Wormhole looks promising.