The official Soylent has a demographic, but the ones on makesoylent.com are designed by individuals and tailored to their needs. There is no need to have the makesoylent app put another standard in place. The recipe clearly states how many calories it contains, all of the nutritional information that is compiled to get the nutritionally complete stamp is with that constraint in mind.
If you look through the recipes you will see that there is a broad range of profiles and demographics which are covered in them, from obese looking to lose weight, to below average weight and height looking to maintain.
You can also easily copy existing recipes and modify them to suit your own needs. Want more calories, bump up the fat or carbs and see how that affects your micro nutrient profile.
Makesoylent is not a one size fits all approach, hence why you can compare your recipe against various RDAs or even make your own.