I really don't think that trying to rotate their feeding will work. First of all because eating together with their mate and flock in ingrained in them and the act of eating together is both a bonding behavior and a social event. Perhaps you could mount a food and water dish on the free standing perch and let one of them out to eat while the other one eats inside of the cage. With the perch placed near the cage they will still be able to see each other and dine together in that manner.
I strongly suggest that you find or order a separate cage so that you can separate them, before the male injures the female. Check with the breeder and see if he has one that you can borrow until you can get one of your own. It is not all that uncommon for the male to get hostile towards the female, especially if the cage is too small for both of them, which is very easy to do. Most of the people that I know of with this problem eliminate the cage altogether and use a bird room approach to prevent this type of aggression.
Please understand that I am not a breeder, but this type of aggression, although fairly common with captive birds, is not a normal behavior and it is totally caused by our manner od breeding birds, and it is more common with cockatoos than with other species of parrots. The aggression part, not our poor practices which cause it.
Based upon my research into this, it is caused by our deciding to mate these birds by introducing them and putting them together to breed and then most of the time separating them after breeding, they would still be placed next to each other, and although they might breed they are not truly a mated pair, which is why the aggression. I believe that this problem would not exist if we simply allowed them to choose their own mates.
This strongly suggests to me that although you may indeed have a breeding pair that you do not have a mated pair. The difference is that with a breeding pair, we made the choice without the birds agreement and with a mated pair the birds choose their own mates.
These are my own thoughts about this and others may hold a different opinion than this.
Regardless of how you choose to proceed with this, either a cage free approach or separate cages, you really can't afford to wait around to see what will happen as the aggression is more likely to continue to increase and become more and more violent until you have a seriously injured or dead bird. I can't say how quickly it will get worse as it could be very quick or you may have some time, but I would not count on having any time and suggest that you act quickly before it gets worse.