I'm pretty new to the game, but does it seem necessary to impose term limits for mayors? How would one code this law for proposal?
I will look into it, but there's a 90% chance I will forget about your request here. It may not be possible, but if it is: I suggest going to the official Eco discord. Post this question in the "law" section of their discord. Those people can make anything a law if it's possible.
I also have a section on my Eco server discord for laws, so check your discord if you have a public server.