This has already been acknowledged within the Soylent community:
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http://discourse.soylent.me/t/soylent-and-food-stamps-ebt/33...
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http://discourse.soylent.me/t/food-stamp-friendly-soylent/44...Within the Soylent community, there are two acknowledged classes of soylent. The two are distinguished by using "Soylent" when referring to the "official" recipe, and "soylent" when referring to DIY versions.
Rob has stated several times that he isn't going to patent the Soylent recipe. The reason is because the only product on the market that comes even close to Soylent for complete nutrition (without lots of harmful other components) is Plumpy'nut [1]. Plumpy'nut's recipe is patented, so even if someone could produce it cheaper, they can't legally produce it.
Rob is keeping the Soylent formula open in large part so that other people can produce exact and comparable versions. In addition, Rob has not only allowed others to develop comparable version, but outright encouraged it. So much so that when NickP developed a tool to develop recipes based on a list of ingredients and individual goals, Rob promoted the tool and gave it a home on the official soylent.me domain - http://diy.soylent.me/
In otherwords, people are being actively encouraged by the founder of Soylent to develop versions of soylent that meet needs that are not met by Soylent. And people are rising to the challenge - http://diy.soylent.me/recipes?sort=dailyCost&pctComplete=0.9 There's even a 100% complete recipe that can be made for $2.45 per day; this works out to about $74.73 a month - http://diy.soylent.me/recipes/low-entry-barrier-soylent
tl;dr - Your concern has been already been acknowledged by the community; there are alternative recipes, including one that works out to $74.73 a month, which is well under the $225 SNAP allowance.
[1] https://en.wikipedia.org/wiki/Plumpy%27nut