If supercharged I think less of an issue than turbocharged.

On intake cycle supercharged, positive pressure is filling the cylinder and nearing intake valve close I can't see a reason why there would be much higher pressure behind the valve than in the cylinder, at that point.

Then of course, the moment the valve seats the compression cycle starts and cylinder pressure is instantly much higher than boost pressure.

I would be more concerned with stability given an efficient supercharger system can increase the usable rpm range by, a lot. (especially centrifugal)


If turbocharged, how much more you need would depend on your drive to boost pressure ratio. If you have something on the small side as far as turbo(s) go, you can have double drive pressure to boost pressure

So, if 25psi boost and 50psi turbine drive pressure, the exhaust valve needs to close against 50psi and doesn't get offset much/at all by boost as the intake valve is opening during overlap.