Not that it massively matters if you are happy with PiVPN of course, but understanding more may help you diagnose issues should PiVPN ever fail.
> Rosenpass is a key-exchange protocol using techniques that are secure against attacks from quantum computers. It achieves the same security guarantees as WireGuard, using two strong post-quantum key exchange methods – Classic McEliece and Kyber.
> To use Rosenpass, you don't have to get rid of WireGuard; Rosenpass handles post-quantum security, WireGuard handles pre-quantum security and high-speed data transmission.
But after that, key and config management becomes a bit more challenging.
I have a bout 14 devices on a VPN, so that uses ansible to make sure all the keys are where they should be, and can be rotated if needs be.
I piggybacked onto the original configuration file format and built myself https://github.com/WolleTD/wg-setup, which helps me validating the correctness and uniqueness of new entries, hacks names into the entries and even updates an internal DNS zone.
I really don't have to care much for key rotation, though. As most of the devices are out of our control anyway, they aren't allowed to connect to anything inside the VPN. It's just for us to connect to them.