That wouldn't be flipping just a side-effect of ownership. Flippers should provide renovation/real-estate as a service with the original owner maintaining ownership until the sale to someone else.
> Flippers should provide renovation/real-estate as a service
That's a general contractor, not a flipper. The key difference is who takes on the risk: if I hire a general contractor and they turn out to be not very good at their job, that's my problem.
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.