I was referring to the cosmetic issue. It seems that that there is a bit of range with what will work although perhaps not be most desirable. On the first pic, one could scratch the rim with the spoke wrench easily. On a Weinmann concave, I believe I used 16mm also because of the concave rim. I am swapping rims from the Mavic to Super Champion 58s which has an ERD that is listed as one mm greater, so still in the ballpark for me to reuse spokes. As repcharge said sometimes they are way short as on one of my old Schwinns that a shop replaced a rim onto 40 years ago. The spokes were probably 8mm short and I rode it all that time unknowingly. I’ve only messed with a couple handfuls of wheels but it seems rare to me to find ones that have the exact proper spoke length. Obviously I’m not talking high dollar stuff here either.