I don’t know what criteria for stealth flipper is. Certainly someone who buys more home than they want, or that they could afford in the long run. Maybe anyone who bought with the intent of turning a profit in the short term (less than 3 years).
The first criteria cannot be determined by analysis.
The second criteria could be, by looking at the buyers income versus loan payment, after the loan resets.
The last criteria is self evident, it someone puts their house up for sale a couple of years after purchasing it, they may be a stealth flipper, provided they don’t have a reason for selling, like job move, etc.