I would say it another way.

If some tasks could be automatized (like loading and unloading an apparatus), then why not having a dwarf as the mean to do so, provided it has been subdued into submission (by use of some potent artifact, a surtling core?).

This would not be unlike a pair of tamed boars that help producing food. And this would populate a player's base with some dull, zombie workers (one per automated apparatus).

Not sure about slaves, But It would be cool to have a few NPCs be able to be hireable and stay at your base. They could be almost useless and I would still think it would be cool.

There could be a event that happens rarely, like a caravan comes by.. You could buy or sell stuff. Useful stuff, silly cosmetic stuff, Hire a few NPC bodyguard people.