Just asked my F/As about this, here’s the response.

The Flight Attendant’s manual states where the bags are supposed to be based on the position they are working on the aircraft. The A319 does have some F/As storing their bags in the 1st Class overhead bins. I am told it’s because there is limited closet space.

I don’t disagree with many of your feelings on the issue. However before you get on the F/As about this, understand they are just following their guidelines and not out to get you.

Don’t like the policy, best to write United about this one.

Hope this clears the air a bit.