Well, I think that math symbols are a good shorthand, but ultimately the patternmaker must acquire some broader understanding of measurements beyond the handful of measurements they normally work with. (They acquire this understanding through working with Valentina, noticing that there are features which they do not need themselves, and imagining how these features COULD be used by others. Also by reading about others’ work on this forum!)
Introducing symbols doesn’t really assist with gaining understanding, it rather reinforces the knowledge once a person has acquired it. It also imposes a system that is a bit awkward and unfamiliar. This would provide some helpfulness to people who are comfortable working with symbols, but most people don’t have this background.
There probably are no Valentina users which use all 300 measurements. But there are cobblers, corsetmakers, bramakers, historical costumers, and 3D printing fashion designers who ARE using this software and who ARE using what some might consider to be unusual measurements. There is a reason why all the new 3D body scanning systems record around 300 body measurements. We want compatability with these complex systems, and we want to support the entire range of clothing possible.