No, Frieza used his maximum power on Namek and was still curbstomped by Goku. The thing is, back then Frieza had never trained because he was just so damn strong naturally. It didn't take that much effort for him to reach the golden form after he started training.
Beerus propably could gauge Friezas hidden potential and what he could become if he work for it. But Frieza never had any reason to work to get that power because before Goku he had never met anyone who could come close to his power.