No, I think it's much worse than that. There's a general sentiment that triple penalties are applicable (or a danger at least) if a seller is remiss in qualifying the lessee/optinee at the time the contract is struck. The idea being that if a few years down the road, the lessee can't qualify for a mortgage and loses all their option premium money, they've been taken advantage of. So, the only safe thing is to underwrite the lessee for a mortgage at the time the contract is written.
Hint: most of these people can't qualify for a mortgage, otherwise they'd just buy outright.
Franky, the FHA should be writing mortgagees, not Joe Sixpack Seller Financing. Seller financing is more often than not used just as rent-to-own furniture stores are: rent seeking of the poor, with them losing their entire invested amount when they hit a financial hiccup.
Hint: most of these people can't qualify for a mortgage, otherwise they'd just buy outright.