Sea-lion will be won by germany anyway its just a mather of how much losses they will have and how hard they can recover on the east front.
And the position of the US, bombing the AB should not make a huge difference, in a sea-lion italy is better used to take over gibraltar so the US also has to take that which might slow them down a round.
That or using their forces to push ahead in the middle-east before the UK can recover.
Bombing the Airbase even with 2 escorts if the UK has its airforces home you are going against 4-6 fighters and the Airbase AA gun.
Keeping the german surface fleet alive and having the extra carrier makes a much bigger difference, UK can only scramble 3 fighters so even against a BB-cruiser-carrier they might even lose, 1 or 2 german air units make the scramble not worth it.