How about just learning to do it yourself with your current script? It's not that hard and a great lesson into scripting.

https://www.starwindsoftware.com/starwind-v2v-converter, it's free.

Add firewall exception.

DNS blockers (AdGuard or PiHole).

If the service is strictly only for you: don't. Use VPN to access your service remotely. If its a service for everyone (like a blog or such) there is no way around it. It does not break any security, but you should make sure that the containers/servers exposing this service are secured as much as possible.

That's normal on this sub. People chime in with their opinion not their experience.

I must stress though that all my matrix systems have unlimited RAM and CPU at their disposal.

They are all federated yes. I did cluster some synapse services but besides that pretty standard configuration.

I guess, if not, you can always add more.

Why did you mix OpenVPN with Wireguard on your VPS when Wireguard alone would be faster?

I have a few matrix servers, one has 1200 members, there are no such issues you describe.