I would like to suggest that you create a new type of thrall the is a Utility Thrall. This could be to equip on elevators and drawbridges. They could also assist crafting stations and give better crafting times.
I would also like to suggest that you could blow a Horne that makes a sound to open your drawbridge if you have a Utility thrall equipped on the drawbridge.
What do people think about this idea? and do you guys have more suggestions?