I agree with this. We were on Apex at the end of March and don’t think that we would do it again. It was hot and to be honest we just didn’t use it very much because there are so many other great spaces on this ship.
Our balcony had two loungers and two chairs when we boarded, not necessary to ask the steward for anything else.
To answer the question if you can open up all the balconies across, no you can’t.