The one bug bare is when you own a few. Firearms and are looking to purchase another (in particular a smaller caliber) you still have to have a 28 day cooling off period .
Example : I own a high powered 30-06 and a .222. Now if I wanted to replace either of those , like for like or I wanted to purchase a smaller caliber, say a slug gun or .22 I would have a mandatory 28 day cooling off period.. doesn’t make sense.