No, Mysterium isn't, but Mullvad just partnered with Obscura to create an onion routing like service. I asked Obscura if it worked with Tailscale here: https://x.com/mdhardcastle/status/1949442089902547039

Obscura

Obscura VPN | Privacy that’s more than a promise

Available for Mac. Download today.

Mullvad VPN

Mullvad has partnered with Obscura VPN | Mullvad VPN

Today we are announcing a partnership with Obscura VPN, a newly launched two-party VPN service that uses our WireGuard VPN servers as its “exit h...