I don't shoot hot loads. I've only ever used chamering reamers for the dies that I've made. And, they primarily neck size only. Everything has worked fine.I didn't know you can make a sizing die from a chambering reamer. I always thought they made die reamers for that purpose. Do you not need smaller dimensions in a few key areas to resize the brass?
Now, if you're talking about hot loads and magnums, then yes, you're probably correct.