Person count automatic refresh

It would be great if, when updating smart lists, the person count could automatically refresh, rather than needing to hit the refresh button. When sending an email, I might need to play around with the smart list a few times to fine tune it, and check the people count is about right as a sanity check. Currently, every edit to the smart list requires me to hit the refresh button, I'd much prefer that the number auto refreshed every time I tweaked the smart list instead.