Yes, the larger breeds I don't worry so much over, my last hen to hatch chicks was an Ancona hen, very small compact bird, raised for tropical climates I got her last year and sold her sister this past spring and was going to sell her but we couldn't catch her 

  Lo and behold a type of bird not known for broodiness went broody, I questioned whether to allow her or not and finally just marked some eggs and let her go, she was in the coop with the other 40+ chickens , chicks and roosters I have.. The first two weeks she would bolt out of the coop every morning when I went in to clean , feed and water the flock but that last week I never once saw her off the nest and mind you I am home most days and out there several times a day collecting eggs.  Even tho I didn't see her off the nest didn't mean she wasn't off the nest, I couldn't get within a foot of her before she would fluff up, growl and pitch a fit so I didn't dare even try to take her off... On day 20 all 5 of her chicks hatched and she didn't seem to suffer any worse for the wear..
 Like I said, we worry and fret over these girls but in all honesty they are doing what nature has allowed them to do for thousands of years. I try to be completely hands off with my hens because of the fact they know what they are doing, they have those eggs positioned where they need to be, lifting a hen off and putting her back may cause her to crush some of the eggs, I know. With my first broody I darn near killed one of the chicks that was zipping and I couldn't stand not being able to see it, when I put the momma hen back I heard a crunch and knew she had sat down wrong.. Thankfully the chick survived but my Sister in law wasn't as lucky, when she placed her hen back down the hen did crush the chick, so when I say to leave them be I am not talking from anything but experience, one that could have been bad. I make sure they have a dry area, quiet and clean. Secured from predators with food and water within site but not next to them, I want them to get up and walk and trust me, they will.