Hard to conclude from my testing how well this toothpaste would work with a properly installed heatsink. I'm guessing load temps would be lower, and I wouldn't use it to O/C. No way to know how long it would last before temps would get too high. But I'm guessing toothpaste could be trusted without prolonged load times (ordinary use) for at least a year with a properly installed HSF.
And now having just read online that the F7Pro comes with a pre-installed high performance TIM, there's no reason to wipe it off and continue testing toothpaste. I'd rather O/C this rig and get on with subjecting it to heavy use.
So my conclusion with toothpaste is what others already knew. It can be trusted to work as a TIM, probably shouldn't be used for overclocking, and temps should be monitored.
I wish they would hurry up and deliver my F7Pro.