Exactly, what I am suggesting is current flippers will guarantee a sale price to the seller, renovate and how much of the profit above the sale price they take

Exactly, what I am suggesting is current flippers will guarantee a sale price to the seller, renovate and how much of the profit above the sale price they take is a matter of market/negotiation. They still take on the risk and work on multiple houses they just now have a seller pestering them to sell soon instead of hoard houses until price is high enough.