It technically is source-available, as of Nov 2024, anyway: https://news.itsfoss.com/cockcroachdb-no-open-source/

So yes, license (and compatibility - see https://pgscorecard.com) are two major differences between pgEdge and CockroachDB.

pgEdge version updates also come in very close alignment with upstream PostgreSQL intentionally to make sure security patches/bugfixes and the latest features get to users ASAP.