It’s just a dicey thing. I read so SO many times about disappointments with cam swaps on heavy vehicles due to cams and there lack of vacuum for the PB set up.
And you're dead on too! Know what you're saying. Too many poor choices have been made over the years.. I cringe every time I hear about it. Lol
We don't hear about RV Cams anymore. Mainly cause they were, for the most part, too small.
By the time a cam was swapped, intake and exhaust bolt ons had already been made.
Everything has its place. Good tip on the MSD BTW!