Im a firm believer that a ballast sac or tank needs passive venting. An impeller pump has enough force to pop a bag. Chit, I even know if an MB that a restricted sac vent caused the sac to pop the deck cap from the hull at the rubrail seam. Im also a fan of having that over the side visual and audible signal that the sac is full, when you see and hear the vent purging.
I 100% agree with this. Not having venting stock is frustrating but with wake boats.....in for a penny, in for a pound.