I applaud your willingness to manage up as well as down. I can't tell you how rare it is for a middle manager to trust the engineers in their charge to make these types of decision. At most places, where bastardized "Agile" has taken root, if any change can't be directly tied to a feature then it's not happening.
I've been really fortunate to work with reasonable product managers. At worst, I've sold automation as an IOU - let me do this 1 thing now, and you get 2 things next release. But, even that's the exception.
