Ah 9/11. Can't believe it's been so long. I remember I was in 7th grade Biology class when they made the announcement over the loud speaker. Canceled all after-school activities.
Is there any difference between Returning a HIT and letting it time out? Just wondering what I should do with my queue.
Functionally no. Neither counts against you except in extremely rare cases where they make "Hit abandonment rate less than x" as a requirement, but I've only seen that a couple times.
One adds to your return rate and the other to your abandon rate. Essentially, neither matter at all, unless the super, super rare HIT that ever uses return or abandon rate in their qualifications, and if you come across a HIT that does, they probably have no idea what they're doing and the HIT probably sucks.