It sounds like your new at this, so maybe I can help. First, reptile husbandry is not cut and dry, you cannot set up your animals like on some caresheet and expect it to go perfectly(all snakes grow well, breed, all eggs hatch, etc) Caresheets are too get the ball rolling so you the individual can actually start to learn about the animals.
In this case, that egg is telling you something, even if its some tiny little thing that is off. So messing with it is and changing the conditions is covering up valuable information you can use to improve your husbandry in the future.
Usually if a neonate does not emerge or slit the egg, there is very good reason for that. Your task is to learn what is causing that.
One egg is nothing I would worry about, if you do your work, you will receive lots of eggs from even this one pair. But if you see a trend of lots of eggs not hatching, then you need to attend to that and learn what you are doing wrong.
I have hatched snake eggs for over forty years and after thousands, I am not sure mucking with them has saved even one individual. U see, they could have made it own their own, if I did not interfere. I won't know if I interfere. They could also die on their own, or I could have killed them by mucking with them. After years of not mucking with them, I have seen eggs hatch that I thought would not hatch and ones that looked perfect, die. They are a bit complicated and conditions can effect all parts of their bodies.
You messing with a soon to hatch egg is never a good thing. It normally does no good and only can cause harm. Remember, most did well in the conditions they were in. Again, one egg, might have had a problem, count yourself lucky. If that egg hatches on its own later, you will have worried for nothing.
Also, give up the worrying, if your going to worry over one egg, your life keeping and breeding snakes will be heck and of constant worry and grief. Take joy in the individuals that did hatch out healthy. Then learn from the ones that don't make it. Then help others learn from your experiences.
No I am not a fan of messing with eggs by slitting or poking. But I do understand why WE do that. We are just curious meddling creatures, who have to hedge our bets. Cheers