IMO just make MREs use the rationing system most people are more-or-less expecting for U4, but with the different “components” of the MRE. That’d be a simpler way to handle it, although it’d be a bit rough around the edges and the rationing system would reflect that with other items because of it (unless rationing an MRE just makes you generally ration out “whatever” is left of it, with disregard to actual separate consumables that’d be realistically in it).