> Is it a good idea to run all sorts of extra stuff on your literal firewall/router?

I don't see any reason not to. I run dozens on services, both bare metal and containerized (Podman) on my router/firewall. It doubles as an all-purpose home server with plenty of headroom to spare. It's just a computer that sits at the edge of my network, and running services meant to be exposed to the Internet on it is natural.

> You also said that Linux has much better performance vs BSD, which seems rather far fetched. Got any data for that?

I should have worded this more carefully. What tends to happen is that BSD has worse (or no) drivers, that's when BSD's performance can noticeably degrade vs. Linux. From memory, people online were reporting issues with Realtek chips. With Intel NICs, the routing performance should be broadly equivalent .