Here listed all api breaking changes.
When something changes capable of breaking things NFQWS2_COMPAT_VER increases.

v2
* removed "stun_binding_req" specialized payload. replaced with common "stun" - any stun packets, not only binding request.
every LUA relying on desync.l7payload should be revised.
nfqws2 --payload option and init.d custom scripts must be updated.

v3
* restructured desync.track. pass positions in desync.track.pos.{client,server,direct,reverse}
code relying on conntrack counters and sequence numbers must be rewritten