ZeroTier is the best overlay protocol MikroTik has ever added. The flexibility and ease of using it are going to give MikroTIk a significant advantage in enterprise networks. It’s also better with IPv6 than almost everything else i’ve used.
I don’t know if they paid for it or not, but at the rate we are doing ZeroTier/MikroTik integrations to replace things like Cisco Anyconnect, Pulse Secure, Fortigate VPN, etc i would say it’s worth it a thousand times over.
That’s not even getting into the OOB, Industrial/Energy and IoT applications.