Yes, I believe I made the stupid mistake of not restarting after enabling. Once I did that the warning went away and I was able to enable subnets, but I’m still not able to see my local services (where I try to access via the IP of the host given by Tailscale or the magicDNS address). So, progress!
ETA: I also had removed the advertise exit nodes line and restarted the container with the --reset flag. After the warning went away I re-added the exit node option and I get the warning that it is misconfigured again.
I may be (probably am) worrying too much about this, but doesn’t that remove much of the benefit of running services in containers? My understanding is that one benefit of containerization is so that if one service is somehow compromised, the others remain isolated, but running the service that allows you inside on bare metal gives single point access to the drives that those other services rely on, and that’s from the most likely point someone could get into your network. Alternatively, if Tailscale is containerized and someone gets in, they have access to the other services’ front ends but not the data they rely on since Tailscale itself doesn’t have that access.