I have 'rescued' Marked Slave cannisters after destroying Kumo Crew ships. Yet, I do not have any options to turned them in any of the Li Yon Rui controlled systems Ive docked at. Even though I have read that this was an option for our specific powerplay, this option doesnt exist in the Power Contacts. Is there a specific station that takes in the marked slaves or am I suppose to pretend Jettisoning them in space stations liberates them?