I've read a bunch of posts about this, but I still haven't quite got it all sorted out in my mind.

My villagers move around just as fast in half-time as they do in normal or double-time, and they seem to learn just as fast in half-time. But they don't age as fast in half-time. So can I keep them in half-time indefinitely, and get more work out of them than they'd do in normal time? Seems to me this would push up their abilities faster, in essence allowing them to learn more before getting old. My goal is to solve all the puzzles without losing a villager to old age.