Currently, the "Sprint Started" and "Sprint completed" trigger in Automation can only run against one specified board.  If I want certain actions to take place after a Sprint is started for all Boards/Projects across my instance, I need to create this same rule for every single Board (assuming I have 50 sprint boards, this is 50 rules I need to write, not to mention the fact that every time I create a new sprint board, I'll also need to remember to write up a new automation rule for it) .  This is a ton of overhead. 

At the very least, I would like to be able to select multiple Boards for the rule to apply to.  But ideally, I should be able to write a rule that executes on a more global scale when any sprint is started.