Ok.Yeah.
I'm still experimenting/learning about using different flours. I buy Namaste brand at Costco, since it's (relatively) cheap, for a GF. Here are its ingredients: Sweet brown rice flour, tapioca starch, brown rice flour, arrowroot powder, sorghum flour and xanthan gum.
For my sourdough, I feed it half and half brown rice/oat flours that I grind at home, because, well, they're cheap. I have purchased tapioca and sorghum flours to use, since so many recipes call for those. The starter seems to like the brown rice/oat mix well enough. The discard makes a tasty pancake too.
One of my books says brown rice flour is good for pizza crusts because it's more coarse than most other gf flours. I haven't make a good traditional pizza crust yet, but based on my experience with brown rice based gf flours that makes sense to me.
I'll pull my books and snapshot some recipes.
For some things I like to use a basic millet and sorghum mix, others the basic brown rice mix, and for breads something I made up myself.
The lighter flours like tapioca, potato starch, and cornstarch are a pain to work with (powder goes everywhere and gets on everything) but they really help add lightness and structure so I suck it up and make big batches of GF mixes that I store in the fridge for quicker baking. Then spend an annoying amount of time trying to get all the fluff cleaned up.