I posted to Mr. Baker in that link above about my .475. You can read his answer there if you choose.
I notice that a lot of guys here are referring to the "performance" they are getting with Lil'Gun, when that is not in question, nor the issue here.
It is the throat/forcing cone erosion that is taking place in high intensity rounds like the .454, .475, .500's etc. Since the .44 operates at much lower chamber pressures, with generally smaller powder charges, and thereby produces less heat, it won't affect a .44 as quickly.
I have been reloading for just shy of 30 years, and have a wide range of experiences with a lot of calibers, rifle, handgun, and shotgun.
However, Mr. Baker has access to real pressure testing equipment, and is in on the firing of more high intensity rounds than most of us will have occasion to fire in a year's time, and I will deferr to him. If he says that is what they have discovered, then I think it wise to listen to him.
As a side note, whether you are using lead or jacketed won't matter since the heat of the burning powder will be the same. The pressures may be a little lower with lead and equal charge weights, but that doesn't affect initial flame temps at the forcing cone.