Actually a bit surprised this isn’t a thing already, but on the Data > Data Type tab, clicking any of the trash cans (even if by accident) removes them, all the work you’ve done and all of the data stored inside of them.
This action should be a warning pop-up for sure.
Perhaps even critical enough to merit a three stage warning:
Click > Are you sure? > Type the name or type “Delete” into the box.
Thoughts, @emmanuel ?
edit: After some more digging there is a way to restore them with the “show deleted types”, so perhaps a non-issue after all but for the purpose of any discussion value, I’ll leave it here for now.