So Disney would know not us. They know average daily changes across the board, unquie accounts doing changes, average changes at what point in the window, start dates and end dates that were booked.
I work in way more complicated systems than
DVC booking. If I had the data I likely could easily come up with an account flagging system in a week followed by a couple months of adjustments.
It wouldn't be perfect but would make it easily manageable as a side task for someone working for DVC to review and catch the abusers.
A good example is the first flagging and first year wouldn't do anything possibly. Instead it would be a look back at higher than predicted changes.
Another good example is the change of when Day 1 was. This would be another portion of the flagging system.
Lots of options for flagging accounts if they cared. They don't.