Shotgun 693 says, and others agree:
Why do you want the very hottest .357?
Well maybe it's just for fun. maybe there is a real need. Who cares?
If someone wants to load the hottest round possible in his .357 or 45-70 or old 30-06, that's what he wants to do. He probably understands that there are 44 mag and 500 mag hand helds out there. The 45-70 shooter probably understands that he can buy a big bore Lott and there are a multitude of .30 cal. super lazer ultramags.
But entertainment, and need, exist where they exist so I feel for the guy wanting to do the most with what he's got even if it's just for a good time.
People put heads and a cam and a lot of other things in their small block Chevy while knowing that there are 600" big blocks to be had. There are still old hard heads hot rodding flathead 1936 Ford motors. Just a matter of taste.
I'm just glad he's shooting, I won't personally get hung up on his load. We, as shooters have much larger and more dangerous enemies than some cat wanting to hotrod the caliber he owns, regardless if it's a .17 or a .357 0r a .577 nitro express.
Don't trample on other peoples fun. Run what ya got and enjoy it, at whatever level of energy makes you happy, that's my take.