4x Dry hopping schedule in primary O2/CO2 question

I'm in the process of getting my house IPA dialed in, and this includes a "heady" style dry hopping schedule (4 different additions 3 days each in a hop sock) in my plastic bucket primary fermenter after the krausen has dropped. In doing so, I'm introducing some O2 into the headspace, and it seems like there is no CO2 blanket left at all after all 4 separate additions have been added. Is it worth rigging up an S30 valve to the lid of the fermenter so I can purge the headspace with CO2 after each hop addition?

From what I have read and experienced I wouldnt worry about it. The little O2 that introduced should be consumed by the yeast each time you add in your hops. But if you want to do something cool and post up photos of it go for it. Its always neat to see home brewers make stuff!