I haven’t tried reversing it like that, but I was under the impression that there were no specific servers or clients in WireGuard land and that both devices had to connect to each other and authenticate.
I have never really thought about how the servers of VPN providers are supposed to work if this was the case.
I guess I just got confused when I tried setting it up someday.
I haven’t benchmarked it personally but apparently tailscale and WireGuard are very similar in performance due to optimization done by tailscale. I think they wanted to push the improvements upstream but I am not sure if that happened or if it’s still waiting.