Can I switch my Non-O visa extension to my child's extension and what are the requirements?

I am doing this process right this second and yes it's more paperwork, although I didn't need photos at the school.

The only real benefit is if you are planning on getting divorced during the visa time period which I understand invalidates the visa.

Getting divorced also presents massive problems for renewal as you need to have sole custody of at least 1 child, in my case we had to do exactly that, take 1 each.

all you'd be doing is "changing the reason for your extension from married to a thai to raising a thai child. financials are the same (except SOME offices for banked money method do not required the 400K baht to be seasoned the 2 months before you apply) but if you're using monthly method it's the same as marriage

Unfortunately it's actually MORE paperwork based on having a thai child if you're married 😛 Because it's all the marriage paperwork AND then the child stuff too, plus pics of the child at the house, in front of their school, etc. The application still gets the 30 day under consideration, and then you go back to get the year inked in.

I think you're no further ahead at all, but I will leave that for you to decide