On the forcing cone erosion issue.
If a load will erode the throat of a model 19 it will do the same thing with a L or N frame 357. The round fires under the same pressures in any chamber, the hot gasses are the same coming out of the brass and cylinder throat and make the same jump across the B/C gap and into the throat. All the blued models use same steel in barrel. So same effect on forcing cone itself. A model 19 does have less steel in this area and will fail from cone erosion thinning way before the rest. But, forcing cone erosion is good for none of them. A 19 that is eroded may crack before the L or N, but prior to cracking could have barrel removed, shoulder cut back enough for a turn or 2 and the cone recut just like and L or N with excess erosion, but who wants to do that or pay to have it done?

Stay away from loads that cause throat erosion be it in K, L or N frame.