I couldn’t swear to it for every style, but I have found that it is just the all neoprene skirts (with the coaming stretch rand rather than elastic bungee in a tunnel) are the ones that need to be sized up.
My experience: My old spray skirt finally fell apart and I looked for a replacement. That model was nowhere to be found so I shopped for different brands. I used their measuring instructions and chart and ordered accordingly. The thing was way too tight. I sent it back and got the next larger size and it has performed beautifully. So, no; spray skirts are NOT supposed to be only used by Russian weight lifters. They SHOULD fit snugly on the coaming and manufacturer’s charts can be wrong. Good luck with your quest.
That is exactly the situation I have. 1.7 nylon…2.2 neo.
Thank you @willowleaf , @Rex , and @Oldboo for that reassurance. I used my 2.2 in some light waves yesterday during my intro to surfing. I’ll give the twisty knee-pop test a try and see how things go from there! Hopefully I can use what I have!