I don't see Expression Maps as a suggestion. It's really a convenient way of setting articulations. Each library has a finite amount of articulations. You have Legato, Staccato, Detache, Portato, Marcato, Portamento. etc. etc. Some libraries have variations of these articulations. For example, with Solo Strings, you have performance_detache, detache long, detache short etc. All these different variations can be neatly organized in an Expression map that can cover almost 100% of the articulation set of the specific library.
It defeats the purpose of trying to make one Expression Map for 4 different string libraries. For instance, I see these "bow" articulations in Solo Strings, that don't exist in others.
I just think well written Expression Maps would add so much value to this great product.