Ok, never had a machine like this before so I just assumed it worked like the new ones. It isn't a problem working the two levers separately.
The hoe works fine on just idle, can fill the bucket without problems. It is the loader that seems to need the revving which is why I thought that the pressure isn't being balanced correctly. No guessing here, I think I will get a 3000 psi gauge and start checking out the high pressure lines to see what the pump is putting out, then maybe the pressure going into the loader. I was more or less wondering what the normal behavior of these old 530s is since I don't have anything to compare to.