I wonder... if you do something with AGPL that requires releasing the changes back ... you don't need to sign a CLA to do that.

However that would also mean that the core project couldn't accept your changes without the CLA since that would also bind them to never switching the license or relicensing your contributions for an enterprise license.

... I think. My head hurts when trying to consider the implications for CLAs and AGPL and the endless debates that lawyers could have over this.