Plating thickness limit

Why we can not electroplate cadmium and some other metals more than certain thickness effectively whereas in electroforming even mm level deposition is possible? What decides this thickness limit?

Sometimes stresses and porosity start making the plating unsound after a certain thickness. One interesting phenomenon to think about is that as you begin plating the plated layer will try to match the crystal structure of the substrate, but after a certain thickness there are few remnants of that original crystal structure as the plated material adopts its own native crystal form.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

Just to add that electroforming normally uses very low current densities and control of parameters which favors small crystal formation and uniform growth. I've never heard of cad electroforming but there are many metals which are routinely conventionally plated and also E-formed (gold, silver, cobalt, copper, nickel).