"it will wreck a Lee PPM"
Hum...
Someone forgot to tell my Lees that they should be wrecked by now from using WW 296, which is the same as H110...
"H110 at max loads wrecked cases quickly"
Define "wrecked."
I've got as many as full-power reloads through some of my .357 Mag. brass and I see no signs of it being wrecked.
"Reducing loads even slighty caused velocity to fall precipitously"
Uhm... Define "precipitiously"...
You're either doing something wrong, or you've got some bizarro situation cropping up. I've never had velocities fall off much more than what I expect as long as I load to within the powder's book range.