My question is: would any minor leak occuring in this area affect the final part finish if the bag itself was airtight, seeing as it is 'downstream'. Pump is left on during cure with no audible indication from it that there's any air ingress when running, but when left for a few hours during drop tests I've heard a slight tone change for a few seconds when opening the breach unit ball valve. I'm even starting to question the quality of the valve itself. I've also considered curing without the pump, but is a pinhole-free finish realistic to expect even with a totally sealed bag and are there volatiles in the material that really need to be evacuated during cure?

Not had a problem with leaks from the breach unit (been using them for 4odd years)