Given that Phalcon uses semantic versioning, I don't see the need to observe strictly the identity between versions of Phalcon and Incubator or Phalcon and Devtools.
We can use the dependence as the "ext-phalcon": "3.0"
or "phalcon": "3.1"
and it is not necessary to wait for the next Phalcon release, we can just release new versions.
What do you think?