If you're already a Tailscale user, seems like this solution is nearly identical to using Mullvad as an exit node.

You would go with this solution if you don't trust Tailscale or NordVPN, I guess.

(Carl from Obscura here)

I could be wrong but in Tailscale if you use Mullvad as an exit node, the traffic flows directly from your device to Mullvad's servers.

Whereas with Obscura, your traffic flows to the Obscura relay, then the Mullvad exit.