Hi folks, for this who need a GF diet there's more to just replicating gluten when baking.
One really important thing that is overlooked is the temperature that a grain starts to cook at (gelatinisation temperature) and with wheat it is 48C potato and tapioca 62C rice 72C soy 79C so this is why most GF flour mixes are mixes and have tapioca starch, potato starch and rice flour, plus they are inexpensive.
I First used to mix a little tapioca starch with brown rice flour and that works really well for most recipes.
For bread I use Doves Farm GF bread flour and add ground chia seeds and quinoa flour and I add sesame seeds, pumpkin seeds, linseed and chia seeds to it.
Egg whites replicate gluten really well and gums like xanthin guar gum and psyllium husk are all good replicators. But they are also emulsifiers so they will bond fat with water and they are very hydroscopic so they absorb a lot of moisture and act like super roughage so you want to go easy on them and psyllium is used in colonic irrigation too.