Having read that document, the ISO 7730 model itself depends on stable temperatures. However, I think the key is simply to understand thermal mass; people can be in hotter air, but feel cold due to cold surfaces (e.g., floors or furniture), which heat more slowly (or lose heat more slowly) than the air itself.

Therefore, 1st: Heating/cooling cycles from your HVAC are fighting these objects because they don't mix at the same speed as other objects (e.g., the air itself), so you end up with gradients across objects; people rate this feels unpleasant.

2nd: Mechanical equipment tends to operate more efficiently under constant load compared to constant start and stop cycles.

With #1 and #2, you can just heat constantly to increase both the uniformity of heating across objects and also the efficiency of the mechanical equipment's energy conversion.

There's a 3rd point, which, really, is just a sneaky way of reframing #1 and #2, and that is that you can also lower your setpoint and still have a subjectively superior comfort perception compared to a cyclic system. It drives home the point to say "constant 68F feels more comfortable than intermittent 72F." But it also invites the complaint about constant versus intermittent energy use, right? So I think just detailing #1 and #2 is better.