The one on Dan is more severe than we'd use on Cyn, because of the hard skinny nose piece. We'd get a nice wide one. I've not seen bare spots from hackamores, but I have from people who leave halters on.
I like them for trail because you can take a break and let them graze or drink without the bit interfering. And I like them for new riders, because they have a lot of stop that a beginner needs, without having a very severe mouthpiece in their mouth.
Well, like I said, the type you use would probably be OK. But still, why do you think clamping something down across the bridge of a horses nose is any less uncomfortable then a bit in the mouth?
Becky