I think that's something a lot of people don't understand. (HIghlighted your comment in red.) Someone will do something and it didn't work for them, (or maybe they didn't do it right to begin with) and then they become staunch "never do this, no matter what" people when sometimes that is exactly what should be done. Alot of people (and no disrespect to anyone) get stuck in their own personal experiences and can not/do not have an open to mind to how someone else does something. Instead of posting from an "in my experience" point of view they post from an absolutely [yes/no] and sometimes are pretty gruff and condescending about it. It's great to have different points of views and different methods on how to, but I cringe when I see someone post from a no-leeway attitude and use the terms 'you should never' or 'it's certain to'..... nothings certain, and tehre are situations where the you should never becomes the exception and you should becomes a in your case, you shouldn't.Make sure the membrane hasn't dried, you can rub some distilled water on it if it dries out. You may want to wait a bit longer just in case the yolk hasn't been absorbed, just make sure the membrane is wet enough and isn't sticking the chick in the shell so it can't turn. If you do intervene, so it ever-so-slowly, peel a teeny bit of shell (tweezers work well for this) , wet the membrane with distilled water (or I've heard people have used bacitracin? Neosporin? I think) put it back in the incubator and wait. Do this in many stages. After a bit a help, the chick may be able to get out on it's own.
I helped a chick out on my first hatch, and that gave me too much confidence, so I helped another one out on my second hatch, which also went fine, but on the third one, which had started zipping, then stopped for about 24 hours, the yolk hadn't been absorbed. I tried putting it back in when I discovered this, but I'd taken off too much shell at that point, and it was scrambling to get out, and broke the yolk. I felt terrible. It's not always "yes do this" or "no, never do that" .
sidenote:This may not always be the case for malpositioned chicks, but the two I did help out ended up having problems (one had leg issues and the other was always about the half the size of it's hatchmates), and both died after a short time.
There is a great article about assisted hatching: https://www.backyardchickens.com/a/step-by-step-guide-to-assisted-hatching
I admit, I did not follow the instructions, and went too fast.
My last hatch I had a very malepositioned chick who was really in a bad postion in her shell. She could not have made any progress no matter because of her position. After 18 hours I widened the hole to see what was going on and when I realized the problem I started my assisted hatch. Very little help, moist membrane replace in bator to rest and give her a chance to make progress. It was a long process and I repeated this about 4 times before she had enough give on the egg shell that she could reposition herself and eventually she finished the hatch herself. She's now a beautiful almost 4 month old pullet. Perfectly healthy, she's my overly eager cockerels object of lust as well. So there is a time and way to help, it's just being able to figure out the when and how that's the problem. Same hatch I had an nn stuck in the shell. Did the same process. (It was shrink wrapped.) It was lively and seemed to be well, but was having severe pasty butt. I used sav a chick, tried the apple vinegar water, to know avail and about a week later it really started to take a turn in the opposite direction and at about 9 days it died. So no matter what help I gave that one, it wasn't ment to be, there were bigger issues that I couldn't fix.
That's a great assited hatch link. I probably read that three times before deciding to help...lol