There isn't a legal requirement set by the government, but local Amphurs can vary (as clearly they do in your situation) in terms of how they deal with applications . It may well be worth going through an agent in your situation as they can talk directly to the officials directly.
Such benefits that accrue from the YB/PC are the same throughout Thailand as they're issued centrally (by the Thai government administered through the individual Amphurs)
Why was it mickey mouse if my translation was correct? 🤔 I didn't need any witnesses either. I did do my interview with the officer at the Amphur in Thai though, so maybe that helps
As one example, with a yellow book and pink card you can buy/sell vehicles instantly without having to go to immigration first. It's not a life changer for sure, but it's more than simply a case of having to avoid getting a RC every time you need one (which is only even remotely convenient if you live close to an immigration office in the first place remember)
I did my own translation of my passport, which was accepted by the Amphur. Some years ago though, and sometimes requirements can vary depending on which person at the Amphur you speak to, based on reports