Anything with bean flour of any sort is an automatic no-go for me (diagnosed celiac 11 years ago). I hate going to a GF bakery that has a case full of beautiful baked goods, buy a $4 cupcake, take a bite, taste bean flour...and proceed to spit it out and cry because I wasted $4 (and really want a cupcake). The people who say the bean flour taste goes away after it's cooked are lying.

I make my own blends, I generally do 200 grams ultra fine brown rice flour, 200 grams ultra fine white rice flour, 200 grams sorghum flour, 200 grams tapioca starch, 200 grams potato starch. It's the closest cup-for-cup replacement for "real" flour that I've come up with. I don't add xanthan gum directly to my mix, I add it as needed as different applications require different amounts. Use 140 grams for every cup called for in a standard recipe.

If you don't want to make your own blend (I would highly recommend making your own), use cup4cup, better batter, I'm limited in store bought options because I'm in Canada, but anything other than bob's red mill standard GF mix is eons better than bob's flour.

So unfortunately the flour really was the problem in this case. I find most mixes to be lacking, they can be spruced up by adding sorghum flour, but if you're going to be doing a decent amount of baking, I highly suggest making your own. It's costlier than buying premade blends but the quality of the finished product is much better. (at local prices 5 lbs of my flour costs ~$15 to make but I use enriched rice flour and tapioca starch, I can buy a decent store brand non-enriched blend for ~$12 for 5 lbs)

For pies in general, Cream cheese pastry is my standby. Regular pie crust made with butter, shortening, or lard turns out perfectly fine with my blend, but cream cheese pastry is SO FLAKY and delicious, and it's so easy it feels like a cop-out. It just works. It rolls out very thin without cracking. It goes into the pie plate without breaking. It browns beautifully. It just makes a damned good pie regardless of the fact that it's gluten free.

250 grams cream cheese (whole brick), 250 grams butter, 2 tbsp sugar (omit if making a savoury pie), 280 grams flour blend with ½ tsp xanthan gum mixed into flour. pulse in food processor until coarse crumbs, smush into two balls, wrap balls in saran, refrigerate for an hour, roll out between two pieces of well floured wax paper. (makes enough for 1 two-crust pie, or 2 single crust pies.)