I spent a great deal of time trying to do this at allofus.ai with a team of ex-googlers with our goal being to help creators eventually 'own' their personas and drive and compete to use them to help end users.

We believed this was coming and that the best way to handle it was give the real person control over their persona to grow/edit/change and train it as they see fit.

I actually own the patent on building an expert persona based on the context of the prompt plus the real persons learned information manifold...