Crowded is not a reason to take them out. If there is room for the eggs, there is room for the chicks. I personally would not like to be that crowded, but I'm not a baby chick. I would not like that 100 degree temperature either.
They can go without food or water for three days. It won't hurt them. I don't like to leave them in there any longer than I have to, but I don't panic if the hatch goes on a bit. Some of my hatches are over within 18 hours. Some take the full three days. Chicks from both types of hatches do equally well when I take them out.
Not opening the incubator during lockdown is a guideline intended to improve your odds of a good hatch, similar to almost all the advice given on this forum. Violating the guidelines does not always lead to absolute disaster. Almost all of us violate some of the guidelines and still do OK. The guidelines do not guarantee either success or failure. They merely improve your odds of success or, if you violate them, you have a greater chance of failure. No guarantees either way. Just odds.
If you open the incubator during lockdown, you can shrink-wrap a chick. It is not that you will shrink-wrap each and every one each and every time. You probably won't. But just because you violate the guidleines and get away with it does not mean the guidleines are rubbish. People do sometimes shrink-wrap chicks by opening the incubator during lockdown. I've done that. The main risk is during pip and zip, since the egg shell is open and the drier air can get to the membrane. I have had eggs that pipped on the bottom where I can't see the pip, or the pip has been moved to the bottom by the early hatchers playing rugby with the unhatched eggs. Just because you cannot see a pip does not mean that one has not pipped.
People that open the incubator prematurely during lockdown either do not really understand the risk they are taking or they understand the risk and are willing to take that risk. That is their choice.
When do I take mine out of the incubator? Ideally, when I feel the hatch is over and the last one has dried off. The humidity gets real high during hatch, so it can take a while before they dry off. After the hatch is over in those long drawn-out hatches, I have taken out the ones that have dried off and leave the wet ones behind in the warm incubator so they don't get a chill going to the brooder.