@Benjamin *****
The nearest equivalent I can think of are Tourist Police Volunteers, which we have in Phuket but maybe not other provinces.
Phuket Immigration Volunteers wear white uniforms with immigration volunteer insignia. They sit at desks in the various rooms at the Immigration Office. If you are a short-term visitor you see them first and they get you headed in the right direction with the right paperwork. (If you're a long-term visitor - like marriage and retirement extensions - you don't have as much interaction with them, especially for annual extensions.) For example, if I want a Certificate of Residence, I would take my paperwork to their desk at the Immigration Office, they would ask what I wanted, check my paperwork, tell me if I were missing anything, have forms if I were missing one, etc., and then when your paperwork is correct (in the form the immigration officers want to see) they give you a queue ticket for the proper desk that does what you want.
By the time a customer gets a queue ticket there are usually not any obvious problems with the applications as they've basically been pre-screened. All this without taking time away from the work that the immigration officers do. They are always there. If they weren't things would work much differently at the office. They are especially nice for people who have never visited the immigration office before.