You know, something else that may factor into it is temperature. Someone (ChicKat?) mentioned that she suspected that high temperatures during a chicken's young life may lead to big combs. Heaven knows my birds (girls and boy) have huge combs here in South Texas, and they were doing their "growing up" in 90-100F heat. And @duluthralphie was initially totally perplexed by big combs on my pullets because his pullets/hens (in Minnesota) had very small combs.
- Ant Farm
I am also familiar with this discussion of temperature relative to cockerels combs/wattles, and have heard it from very well established breeders. I just haven't found that to be true in my breeding groups, as brothers from the same hatch will show variation in comb/wattle size. Nor have I noticed that time of year makes a difference i.e. cooler weather vs warmer weather. Maybe there is not a significant temperature differential in my area.
I have found that crest size affects the shape of the comb and all things being equal, am trying to breed from hens with small neat combs.
That having been said, I am a fan of all size and manner of crests in the CL and enjoy the variety, including color variations. I know, not in keeping with the SOP, but I still like the variables.