Being inexperienced I’ve taken the dont assist approach always. I’ve assisted the last hatching eggs that just needed some help breaking out of the shell probably due to the bator being opened.
I had 40-something eggs make it to lockdown in my first hatch, they were virtually all shaking around and many chirping but I only hatched 25 or so I think. I didn’t open any of them because I didn’t want to feel like “what could have been”....
There are a lot of very experienced hatchers that swear by the "don't assist" approach and there's nothing wrong with that! It's how nature does it and they seem to have things down pat, lol.