> Tailscale needs to know information about your Mullvad license in order to authenticate you with the exit nodes.
That doesn't sound strictly true.
Mullvad and Tailscale need to settle their costs between each other, and Tailscale needs to settle with you.
What Tailscale needs to know about "your" Mullvad license is that x of y devices are using a Mullvad exit node, so they can charge you for y.
What Mullvad needs to know is a high water mark usage (data transfer, throughput, connections, whatever) for Tailscale (not you) so they can charge Tailscale some carrier grade rate.
There's little reason Tailscale couldn't do a iCloud Private Relay style Apple<->CloudFlare privacy preserving handoff.
That doesn't sound strictly true.
Mullvad and Tailscale need to settle their costs between each other, and Tailscale needs to settle with you.
What Tailscale needs to know about "your" Mullvad license is that x of y devices are using a Mullvad exit node, so they can charge you for y.
What Mullvad needs to know is a high water mark usage (data transfer, throughput, connections, whatever) for Tailscale (not you) so they can charge Tailscale some carrier grade rate.
There's little reason Tailscale couldn't do a iCloud Private Relay style Apple<->CloudFlare privacy preserving handoff.