Well I've officially sent them a bug report during Early Access and I've officially sent them a bug report now in full release. Both times with videos, full detailed explanations and save files. So lets hope they do or I just wasted my time for nothing
Until they fix it though you can summon them in battle and have them killed by NPCs or simply talk to them and then kill them right after the fight, as they won't regenerate HP automatically. They despawn after 2 turns, so that's enough time to kill them.
Still persistent. Even if you manage to kill them, you won't get any XP out of it...
Pretty sure they're not supposed to grant any XP since it's granted as a part of the Persuade/Deceive solution. In full release peaceful solutions give full XP that NPCs would normally give by killing them. A major positive I say ^^
