If we consider that the new Pattaya immigration rules hold (yeah, I get that it's not officially confirmed, but right now it IS the process at my school) and I pay the 5000 baht for the school to handle the paperwork for my first extension, I have a few spinoff questions:

Does the paperwork that the school takes to immigration cover both my extension of stay and my 90 day address reporting? In other words, do I need to make a separate trip to immigration outside of picking up my passport the day after my school gets my extension processed? If not, is there any additional paperwork that I need to provide the school to complete the address reporting? Perhaps a copy of my rental agreement with a copy of the owner's ID card? Or am I wrong and 90 day extension of stay and 90 day address reporting are not actually two separate things?

Also, my son is here on a dependent visa based on my ED visa. Will I need to make a separate trip for his 90 day extension? Does he need to be with me or can I do it without him? Can I send his passport with the school and have them do it all at once? That last might just be a question for the school, but I thought I'd throw it out there.

There being no law or regulation about it, this is obviously a matter for each individual school to decide.

That's fair. I'll talk to the school.