An interesting discovery: this utility combined with Runesmith allows you to port your Adventure Mode characters directly into Fortress Mode, by retiring them in a settlement, and embarking atop it. I just tested it with the most unusual set-up I could think of; an Elven adventurer who "rested a while as a peasant" at a Kobold cave. I embarked atop it, and used Runesmith to make the Elf Tame, and this utility to enable Elven Slavery. The end result was that my adventurer became a member of the Dwarven civilization, could be given any dwarven work, ate food and slept, retained all his adventure mode skills/equipment, and could be appointed to military or noble positions. It also revealed my adventurer's personality, likes/dislikes, and so on, which are hidden in adventure mode. This opens up some interesting possibilities!
It wasn't perfect though; the elf would not form any relationship good or bad with any of the dwarves. Past modding experience indicates that grudges/friendships are limited to race, and may be permanently stuck at their default for non-civ races. Not certain on that though. Also unfortunate, after abandoning the site, the adventurer was corrupted; though visible in the Adventure Mode start screen, the site to which he belonged was non-existant (since I'd abandoned) and upon trying to load, DF crashed saying "Adventure Location Data Missing/Corrupted" or something of the sort. This means that once you turn them to civilization entities, you can't turn them back.