Can/should I par-bake the bottom crust on a double crust apple pie?

You could but you really shouldn't need to. Aside from the standard measures (which I've always found quite sufficient) there was an article here recently about using almond paste to seal a bottom which you might look into. And maybe stay away from Honeycrisp apples, which have more moisture than most- they're awfully sweet for a pie anyway.

Hi! I'd say a resounding yes! Our resident pie expert Erin McDowell has lots of tips on the technique (here: https://food52.com/blog/18422-par-bake-your-double-crust-pies-join-the-anti-soggy-crust-crusade) as well as other ways to rid yourself of soggy pie bottoms. Nobody wants those!

some people do this but it compromises the border when attaching the top crust. i'd prefer to preheat a baking stone for 45 minutes and/or bake on the lowest shelf in the oven.

Yes! We actually posted an article about this just recently: https://food52.com/blog/18422-par-bake-your-double-crust-pies-join-the-anti-soggy-crust-crusade

And this recipe (https://food52.com/recipes/6715-brown-butter-and-cheddar-apple-pie), which is one of my personal favorites, uses that same technique.

Good luck!