GM's Discretion
One of the major rules of the game is the discretion of the GM (Game Master). Be it rulings for determining the frequency of an object foraged, the difficulty of Skill Checks, Combat Encounters, or determining the effects of Character-specific Quirks., it's the GM's say. The rules in this game are malleable, and can be adjusted, added to, or discarded at your leisure.
This is also an Expansion-centric game, with a heavy (ha) emphasis on Weight Gain. If you want to incorporate your own flavors of Expansion, like Inflation, Blueberry, Vore, or anything else, you're more than welcome to do so! This game only ever used d6's, so it wouldn't be that hard to make something up on the fly. What's important is that you can settle on something you and your players will find interesting and exciting!
The main point is that you're having fun!