I do cut once I see a couple pips, but not before then.

The problem with cutting early is that sometimes the actual temperature in the egg box is a degree or two lower than the temperature where the probe is. Which effectively means you're cutting a day or two (or more!) earlier than you think you are... and that increases the cross section for bacteria and other bad things getting into the eggs' blood supply. And then you have to do the saline wash, and all this other extra stuff you normally wouldn't have to worry about.

If you really are going to cut at either day 52 or day 54, and there's no talking you out of it... then I vote day 54.