I'm wondering how to properly downsize

I've been in chastity before, the maximum was a month but my current cage is about 2 inches and it defo isnt small enough(Doesn't really squish my penis down much and just makes erections uncomfortable). When I first bought it I really didn't realize how much the penis can squish down and I want to downsize a lot but is going to a cage thats 0.7 inches too big of a jump? I'm still pretty new to this and don't know much about downsizing so any advice is helpful.