Thanks for the details, it's definitely believable, but if the user had not consented to have their conversations used for training, then shouldn't it be straightforward to state that their conversations were never used for training?

If you need to do a whole series of extensive experiments to check in that scenario, it implies there are pathways for your conversations to end up in training even though you opted out of that setting.

Of course, this is assuming that the toggle was set to not consent to training. I can't know that of course, but if this is considered a possibility even after using an enterprise account or toggling off data retention, it's a bit concerning.