Are you just talking about the kick issue here or are you meaning they are built too light (components like alum. receiver, etc.)to stand up to the magnums?
Kick issue ..I know the newer stocks are better designed for properly transmitting recoil then the older models. As far as strength ask Z-hat gunsmithing about their strength ..they have a small cottage industry building these guns in DG calibers. Why would a company in todays litigation crazy society build a lever actiongun in 300 win mag or any of the WSM's.? Rotary Bolt locking in a barrel reciever is along for the ride anyway.