Yes i know hill breeds don’t need a lambing shed or field shelters but if you can give extra care why not is my thinking.
Field shelters if you're short of natural shelter? Yes of course.
Taking a hill sheep to live and lamb inside? Recipe for all sorts of disaster in my (fairly considerable) experience.
Hill sheep expect and need space, to be able to go off and select her spot, nice and private away from the flock, to lamb. Once the lamb or lambs are fit enough to run about and bonded enough to follow mum, maybe the next day or may be day 3, she'll pick her moment and gently introduce them to the flock. Over the next 1-2 days the little family group will become more integrated - but given the choice, hill sheep don't really live all bunched up together at these times, they'll be spread fairly widely.
All of that natural behaviour, all of it, is quashed if you bring them in. The ewe cannot do any of it the way her instincts tell her to. Now you have a shed full of stressed sheep, all far too close to each other.
I could write pages...
If you want to have sheep indoors for lambing, there's absolutely nothing wrong in that. Goodness, we work hard enough looking after these critters, may as well do it in ways that give you the most joy! But if what gives you joy is hands-on, interventionist lambing in a nice shed, then please choose a breed that suits that system. And that's not a wild little hill sheep.
Top piece of lambing equipment for hill sheep? Binoculars.