Hallo Edgar!
There can be many explanations for getting an excessive amount of oil from the breather. Is it really that big an issue for you?
Connecting the breather to the airbox is not helping much. The lower air pressure in the air box helps sucking out the air/oil fume. A restrictive/dirty air filter can do that. A separate breather connected directly to the air (not air box), can reduce the oil loss.
If the foam in the breather has become soaked, it doesn't breathe very good, causing a higher velocity on the smaller air flow, which in turn carries the oil better.
Increasing the breather area is generally a good idea, as it lowers the air velocity.
You will need to avoid direct oil splashing on the orifice of the breather stub from inside the engine.
Higher rpms during longer periods, higher compression ratio and worn piston rings also increases blow-by, and carries more oil through the breather.
I have kept the breather connected to the valve cover, but added one through the hole where the starter motor used to be. I'm running 13,5:1, revving +6k all the time with a 680cc. No problem with oil from the breathers (the coffee perculator, according to Bushie).