I have been testing the Tailscale implementation, and although a couple of features work, quite a few important features do not:
Subnets behind other endpoints
When connecting to Tailscale, there is no option to allow the router to accept advertised subnet routes from other nodes. Therefore, these subnets do not appear in the routing table.
Tailscale has the ability to advertise DNS servers to it’s clients, so that clients can resolve internal DNS names. However, the tailscale implementation (at least the AX1800) does not propagate split dns settings to the dns server running on the travel router.
Custom exit nodes
The custom exit nodes slider has a comment about allowing subnets from the device using the Tailscale admin console. For me that did not work. No subnet appears in the admin console for the router. Also, I was not able to reach the internet when using an exit node (checked the ACLs)