Two more hints: Hamarid suggested grating frozen butter and then
sticking it (and Crisco, if adding that too) in the freezer for 15 minutes before blending with flour. I do that for everything now: scones, biscuits, etc.
Next hint came from pie expert (?) that Pat in NoCA was working a class with. Pat passed along my problem, which is: 100% butter crust "melting" while baking.
Expert said to refrigerate the dough AGAIN after rolling it out, forming and crimping it. It should go in the hot oven as cold as possible to get that steam/layering reaction with the protein & fat.
I haven't had any fruit worthy of a pie since getting that hint, but I know now to give it a try.
I'll see if I can get that expert's name.