I have pondered this myself, as I am always one for experimentation when it comes to training, but the overwhelming reason why you wouldn’t want to do this is recovery.
The biggest way to work on weak points is to technically master the main lift. Â If you are performing variations of the main lift on other days, you will never be recovered and able to hit the main lift as hard as you’d need to.
Next, if you’re swapping upper and lower accessory movements, you’re talking about loading your back 4x a week. Â You don’t have to be a rocket surgeon to figure out that in the long term this isn’t a good idea. Â Don’t forget, if you’re benching properly, this will also tax the back.
You can only benefit from what you can recover from. Â If you’re digging a hole too big, you’ll never be able to crawl out. Hit a lift hard, recovery and then hit it again. Â If you’re doing it right, there will be no reason do look for extra work.