Yep, openvpn with factory firmware. It even had a (limited) choice DDNS services for self hosting, on a cheap consumer router. I could never figure out if NAT hairpinning worked though.

Almost all routers have an “advanced” section where you get a lot if these nice options.

I have only bought a ubiquiti device in the last few years though, so I guess it is possible that routers have been enshittified like a lot of tech products with features locked behind a paywall.