BB's are very much affected by any cross winds. There's NOTHING that will correct that...it's inherent in the system. Some setups are better than others, but they're all affected the same by the wind.
If you've got a good distance to shoot...say 100' or so...with a decent back drop (usually treelines) so you can see your BBs then take a bit of time at the next game to set up your rifle/bb/hopup. There's no other way to do it without the range to see what your BBs are doing.
Now...if you're getting a pronounced and consistent hook/slice...then your hopup nub might not be centered. That'll show up pretty evidently. But if you're getting a gradual/variable (with the wind) slice/hook at the last 3rd of your range and the first 2/3rds is about as straight as you can tell...then you're probably setup ok (at least to start).
Heavier BBs will reduce the deflection from the wind...but won't eliminate it. 0.30's will still get pushed off quite a bit in winds.
When you're setting up...forget looking through the scope when you're setting your hopup. You're just looking for the flatest/furthest shot you can get. Once that's done...then zero your optics to match up where your shots are hitting. Zero in close (say 30'), it's easier to get on...then fine tune for further out.
You need to set your hopup for each BB weight (and between brands). Start with 0.30's. Trying to zero and adjust hopup with light bbs outdoors is just approximate.