Over time, I've come to the position that it's a formality thing, that dropping the prefix is akin to calling Robert "Bob", which sounds pat, but it really does cover all the edge cases: Some Miqo'te prefer their tribe letter dropped, so they'll say "Call me Kayah". Others don't like the sound of their name without their tribe letter, so they'll insist on keeping it. Some like to let their friends and family use a more familiar form, etc.
I don't think there's a cut and dried guideline for all Miqo'te here, though. In the case of K'mih, for instance, her name sounds good with the prefix but a little awkward without it, so I could see her wanting everyone to call her K'mih. C'kayah is a little tough for non-Miqo'te to pronounce ("Ka-ka-yaH"), so he's perfectly happy with people just calling him "Kayah" - assuming he likes them. He has been known to bristle at people who call him "Kayah" without his permission.
I don't think there's a cut and dried guideline for all Miqo'te here, though. In the case of K'mih, for instance, her name sounds good with the prefix but a little awkward without it, so I could see her wanting everyone to call her K'mih. C'kayah is a little tough for non-Miqo'te to pronounce ("Ka-ka-yaH"), so he's perfectly happy with people just calling him "Kayah" - assuming he likes them. He has been known to bristle at people who call him "Kayah" without his permission.
