But, the original edging worked for other testers.
So I decided to include a second edging, pictured above. It's four rounds of single crochet, while the original edging only had two rounds.
It works to the same measurement as the original edging, only it's firmer.
These two options in the published pattern will be called A Snug Edging and a Comfy Edging. Some people like an edging that will keep their hat on in a windstorm, while others prefer a looser edging that won't flatten their hair.
It's good to know that when a hat is slightly loose, an extra round (or two) of single crochet might create the perfect fit.