Oh ya, I'm one who prefers to give my hens nothing but the best, and I would rate the properly dried and crushed egg shells as one of the things you can do for hens that they will enjoy and also benefit from the effort it takes, rather than simply throw them in the compost. If your hens prefer them over oyster shell, why not feed them back to the girls when they are available?
Sometimes a little extra work is involved that's true, but the rewards that come from the extra effort is worth it to me and my hen's eggs. In this now throw away society, calcium rich egg shells is a good example of raising green..... I think it is wasting good free nutrition if you don't.
bigzio