Funny you say that. Last night I added several to the settlements. I haven’t really thought to look if they used them yet or not.
Since the evil that is Todd Howard has seen fit to withold the Creation Kit/Geck until 2016, I cannot bring boobs to the boobless of the wretched wasteland with my version of Lydia from Skyrim carrying my burdens, so I am forced, in the meantime, into taking out my frustration on an increasing body count of vermin ;)
(SEMI-SPOILER)
Best scare I had was a legendary deathclaw popping up out of nowhere and not the scripted one early on.