Well, I've found what I surmise to be a bug (or I'm just missing something)... I can't seem to make more supplies (using MKS) than is consumed; it's as if any supplies made are instantly consumed, as the supplies appear to be consumed at the same rate as without creating supplies. Without any Kerbals, supplies are generated, but with Kerbals, supplies are consumed; I am sure I am creating more supplies than are being consumed, as the production tab in that MKS info window shows production of supplies at a rate greater than I believe the consumption is (1.08 per Kerbal per day, by my estimate). However, I added a test converter module to a part of mine to see if it was actually to do with the supply generation, and that worked (although it just converted a little bit of electric charge to supplies, not using mulch or anything), so I'm not sure if it's a bug or I'm just doing something wrong. I have tried several configurations of MKS modules, which, as mentioned above, worked as long as no Kerbals were in the vessel.