> ability to stream US TV when abroad (by exiting from my home network)
Should note that Tailscale does not work natively with hdhr for mpeg television streams b/c wireguard doesn't natively support udp multicast/broadcast. Also can't directly port forward b/c hdhr sets a default ttl of 2.
My understanding is that most VPNs in general don't support udp multicast due to operating on the network layer rather than data link, though iirc OpenVPN supports multicast traffic through its virtual TAP (Layer 2) rather than TUN (Layer 3).
Tailscale does create a TUN/TAP virtual network[0], though udp multicast is still not natively supported.
By 'stream US TV' I assume they just mean using popular streaming services like Netflix. If that's the case, than UDP multicast packets aren't involved at all, since it's all unicast.
Your advice would apply if they're using a local TV tuner or IPTV setup to share live TV on the local network or something, but that seems unlikely. But for content coming from mainstream Internet streaming services, it's good bet they're not using multicast.
For $5 a month you can also get a Mullvad VPN exit node. It’s billed directly through Tailscale which makes it painless.
When I’m outside the U.S. I get much better speeds through the Mullvad exit node than through my (U.S.) home exit node. I’m not sure why, since my home internet is gigabit fiber and I confirmed that I had a direct connection (no DERP relay).
Where's the Mullvad exit node located? It may just be geographically closer to your travel location than your home is. Even if it's about the same distance geographically, the routing path is different and traffic to whatever datacenter is running the mulvad node can be routed to more efficiently than your residential ip.
poking around with MTR (traceroute and ping combined) using various exit nodes and destinations would give you some more information if you're interested.
Set up a US device as an exit node, and configure other devices to proxy through it.