@josh.greenfield ,
The concept of “heat gains with thermal lag” doesn’t really exist in a physical sense. You can imagine that you have several sources of heat (let’s say electric lights, equipment, and solar) and they all radiate heat to the floor slab. The slab absorbs the heat and then, depending on the temperature that the slab gets to, it starts re-radiating heat to the other surfaces of the zone and convects to the zone air. At a certain point, it isn’t really possible to say how much of the heat reradiated by a given zone surface is the result of the lights, equient or solar because it’s all been mixed around and it has interacted with the other heat sources
What you can do is try to visualize the whole energy balance at each time step over the day. This will show you how much of the incoming load is being stored in the zone mass vs. being sucked up by the cooling system.