That was our reasoning for it, a prison sentence would not be a lifetime as people fear, but more of an inconvenience. Kill orders might take away a skill or 2 which while annoying, isn’t as annoying as spending the better part of your day locked up. An easy way to not let stun weapons be abused, is after say a 30 second stun, you have a 5 minute timer, before you can be stunned again, done by game mechanics. 30 seconds with a seasoned group would be long enough.
when it comes to slavery systems, you also have to think about food for however many people you are trying to force to do things, water, oxygen, and so on. And if you cannot get them to “work” for you, than it’s wasted resources.