My student wsnt really interested in a system he was more interested in members of populations. So yes he did require and end point of the expansions when doing a characteristics determination. He inserted brachiopods and trilobites in the Silurian /Devonian and compared evolutionary expansions(size, species /unit time etc) to the actual number of species of brachs seen from the fossil record. He was an Appiled science masters in Geosci and computer science (He is now a very wealthy kids who has developed a whole bunch of decision making software for gas field work).
Im npt sure how I would develop a model that would be "Hands on" with using an energy budget. AFter all, taking a cheetah, they are big overusers of their mitochondrial instructions. For a cheetah, I wonder how a "red queen" expansion between prey and predator would work.