OK... so as Murphy would have it... about a minute after I posted above, there was actually a response. It seems they both will use any private data that I use to build a customer GPT, anonymise it, but still take it and feedback to further "improve" the overall service. Seems like the Enterprise plans are the only ones that will truly keep your personal data... personal. Fair I guess. I'm sure the consumer Pro plans are barely covering costs, if at all.