Interesting. I haven’t had any problems myself getting a bready or cakey soylent just by adding baking powder, a little lemon juice, and water. Baking soda reacts to acidity, not salt, and baking powder doesn’t even require that - it’s designed to carbonate when you add water.
My DIY soylent uses oat flour in a comparatively smaller ratio to the carbs in the official soylent (100g a day vs. 110g oat + 165g malto). The need for gluten is handled by the rice (for the official Soylent) or whey protein (in my DIY) in the mix.
What you mention isn’t a unique property of gluten; it’s protein chains in general, specifically ones in liquid suspension like eggs - that’s how you make meringues, after all.
I covered exactly this issue a couple days ago. Actual vitamin breakdown due to cooking is far slower than most people think it is, even for something such as vitamin C. Worst case, you’ll only be a little bit under.
This was EXACTLY what I did when I needed to make anew batch with no oat flour on hand. I bought a ninja blender and used the instant oats at home…
Update: I crunched the numbers on using rolled/instant oats instead of oat flour. Giant nearby sells 42 oz (2 lbs. 10 oz) of instant oatmeal for $3.39, which comes out to just over 8 cents an oz. 50 lbs. (bulk purchase) at this price equates to just under $65. Honeyville sells a 50 lb. bag of oat flour for $49.99 plus $4.99 shipping, a total cost of $54.98.
Not factoring costs for bulk storage (which is an upfront cost that would be amortized over the long run) or the utility value of convenience for the smaller , beating that price on a grocery purchase would require a price of $2.88 or less. If you shop around, you could probably find something close to this on sale (I’m thinking Price Rite), making this far and away the cheapest option.
For me, the convenience outweighs even the $10 difference in price.