Oh, neat! Never noticed that option in the Wireguard app before. That’s very helpful already. Regarding your opnsense setup:

I’ve dabbled in some (simple) routing before, but I’m far from anything one could call competent in that regard and even if I’d read up properly before writing my own routes/rules, I’d probably still wouldn’t trust that I hadn’t forgotten something to e.g. prevent IP/DNS leaks.

I’m mainly relying on a Docker and was hoping for pointers on how to configure a Wireguard host container to route only internet traffic through another Wireguard Client container.

I found this example, which is pretty close to my ideal setup. I’ll read up on that.