I'm a bit confused on ring sizes after trying a ring sizing kit from a cage maker, I found that i fit well into a 2 1/8" ring (about 53.975mm). But I'm curious if its possible for me to maybe fit into a 50mm ring or it its not possible to fit into that small of a ring size with out it hurting.
I've not used a ring sizer, but if it is supposed to give you the best fit, I'd go with ti. I find some variation as to what ring fits best with different cages, but for most I use the same size. I'd try the recommended one first.
How long did you test the ring for? I'd say go with the smallest size that doesn't cause any pain or abrasions over the course of three or four days of continuous wear.
I’d order one that fits and the next size smaller because you often need a smaller one after few weeks of use.