This sounds like a wildly distributed organization of variables. It is very prone to errors if you pick the variables from different workspaces. Using inputs and outputs is much cleaner.
It is hard to give an explicit answer, because your question is vague only. Please note that the meaning of "sets values to a range of variables, prior to running a GUI which calls on those variables" is clear to you, but nobody else here knows, what you are exactly doing. The term "active in the workspace" might have a distinct meaning, but each function has its own workspace and the worspaces of other functions are gone, when they they return to their callers.
