Yes, open them. The humidity will fluctuate, but don’t panic. It will settle back in. Actually, I think vents should always be fully open from day one.
And for the record, I open my incubator all thru hatching and still have good results. Shrink wrapping is not immediate, as long as you keep an eye on the humidity and do what you need to do, quickly.
But I’m also a hands-on assister. I hatch breeds that often need assistance, so it’s all in the technique.
There are arguments on both sides and I’m not trying to start an argument or disagree with anyone, just stating my position.