So it is clear that kerosene fueled engines use two fluids for film cooling via injection in the combustion chamber, throat, or nozzle. (That is "true film cooling" and not just a fuel rich outer ring at the injector plate.) First fluid is exhaust from gas generator. Second fluid is plain RP-1 from propellant tank.
Q: For the second case of RP-1 film cooling what is a typical value for the mass fraction of total RP-1 mass flow that is used for the film cooling? What, for example, of total RP-1 flow did an F-1 use for film cooling?