Locating bream beds by smell is not difficult,but in my experience I’ve only smelled them in shallow water.I know where to find bream beds on my home lakes,and unless some major event changes things,they are there year after year.
I know I’m in an active bedding area by the noticeable smell,less active no doubt would have less or no smell.Dont overthink it,you will know it when you get near it,but don’t fishing just because you don’t smell them.