that's the dictionary/object project you've already seen, which carries over to the various places i would use it
i would also likely much prefer scripts from having access to global variables in some cases for libraries that need to sandbox scripts in certain ways
i remember i need the inheriting for quite a few features of the dictionary/object project, and there were other things but i can't quite remember them at the moment.
i don't know how the internals of snap handle "script scoping" (it shouldn't be called that) but it does allow each environment to inherit everything from another by adding to it (object with assoc block in the object/dictionary project), and sprites can choose to inherit whatever properties they want, so i get the feeling that inheriting from whatever should be possible without redesigning how variables work