How much of fat from a fat transfer is permanent?

You can read this article from Cleveland clinic if you have not - https://my.clevelandclinic.org/health/treatments/24027-fat-transfer

If you want to remember one number, remember 30% or 1/3. It is inversely proportioned to the amount of fat transferred and the recipient area. For example, if you transfer a lot of fat to a small area, the chance of survival drops below 30%. There are also harvesting and injecting techniques that can optimize the permeability of the transferred fat.