there’s a gap on both, just in different places and you can get from one to the other just by sliding. The constraints are elsewhere so wouldn’t allow you to twist.

It is a different definition, but it’s the same unit… it’s also more like saying “that ball of yarn is 10 metres” - the ball itself isn’t 10 metres long in any dimension, but the meaning is clear given the context, as it would if you said “it’s 0.05 metres”. By having two meanings distinguishable by context, it seems like two definitions to me.