EM, the insight I have on repair time is this. A ball mark properly repaired will take a few days to recover. One that is not repaired, or takes a day or so, can take as much as 4 weeks to "heel" up fully.
When I learned the game of golf back in the day in Chicago, the guys that taught me the game also owned the course I played at, and are still great friends of mine. Jay taught me this and always told me, whenever you walk on a green, always fix your ball mark plus at least 2 others that have been left unrepaired. His message was that with stewardship like that, the greens would stay in top shape. That was almost 20 years ago and I always heeded his advice.