This seems really complicated. Is ZeroTier closer to an cjdns- / i2p-style system, or is it closer to CurveCP/MinimaLT/QUIC? (QUIC being the odd one out of the trio as it grafts on some awful HTTP semantics, but that's Google for you.)
ZT is designed to just be an end to end encrypted virtual LAN for anything you want to dump across it.
There's also a library implementation which effectively gives every app its own cryptographically-derived address (if that's what you're into).
What specifically do you mean by that, and are you sure that it still applies to the IETF version?
I've not read about the IETF version; I'll look into it.