I just wanted to throw this question out there:
We use a Scrum board across many projects. We group our stories into sprints based on the fix version on the stories (so all issues for Project X v1.2 will be in the same sprint). We sometimes use epics to help with this. However, in this case, it would be simpler to just have the fix version display on the stories in the same way epics do. Would this make sense as a new Greenhoper option? or would this not be considered best practice?