Hi, i think cutting your eggs at day 52 would be ok. Just don't hack into them and try to cut as little veins as possible. I cut all my eggs at day 53 and have never had any issues with them. I kinda had the same issue that i went out of town, since the babies are already breathing air before they completely come out of the egg it should be no problem leaving them in the bater for couple days. This is just from my personal experience. And as for the probing i hear of people probing babies all the time. Just be gentle. And you should have no issues. Hope this helps