True. I actually did that at one point but that has it's own issues. If rule B is used by more than one rule or you add another rule that uses Rule B you have to edit rule B. This is what I am trying to avoid.
I already have a bunch of rules that use private boolean, as do many others, I would have to re-write them to use a GV. I just figured it would be easier for the target rule to report back that it finished. Since you can set the private boolean for other rules I figured you might be able to read them.
A boolean GV would accomplish the same thing but the private boolean already exists in all rules, no need to create it. The GV is basically a duplicate of something that exists already in this case.