I would keep a close watch on it & really make certain the area it has chipped away is enough that it can breathe. I have two standard Brahma chicks that I just assisted earlier this morning as they were pipping at the small end of the egg. (I've never ahd that happen before so it was a new experience for me after all these years.) I don't believe they would have made it without my help. They're up now, fluffing out & looking fine. (They have huge feet).
I know others feel much differently about assisted hatching, but I have done it more than once. I've never loss a chick that I did that for though it's certainly possible if you aren't very careful. I have lost some that I didn't , & maybe would have if they had hatched anyway. Who knows? Sometimes it's a gamble. It may not be the time yet - just watch, but sometimes it is necessary in my opinion. I can tell you are concerned. I know the feeling! There are some videos on YouTube you might view if you're interested.