Pyrex pie plate on hearthstone I recently read that one of the methods for keeping the (non-blind-baked) bottom crust of a pie from getting soggy is to preheat a baking pan with the oven and bake the pie on it so the bottom crust essentially bakes before it has a chance to absorb too much liquid (http://www.thekitchn.com/5-ways-to-prevent-soggy-pie-crust-tips-from-the-kitchn-212434).

The article is mum on whether this necessitates using a metal pie pan.  I only own Pyrex pans and I generally keep a hearthstone in my oven due to all the bread I bake, so first, do I risk cracking the Pyrex by immediately placing it on such a hot surface and will my hearthstone work just as well as the pan or should I use a pan for some other reason?
The stone should work just as well. And you'd presumably put the pyrex dish on a preheated oven shelf without worrying. That would give more thermal stress because some parts of the dish would be heated much more than others. 

Of course there are no guarantees. And (domestic) pyrex literally isn't what it used to be at least in some countries.