Trying to clarify... Can I get 60 day visit Thai family extension once per entry, per annual extension, or per Visa?

This may vary on which immigration office you go to, but what are the needed documents to apply for a 60 day extension based on visiting family. I am currently on a 90 day Non O visa due to my kid but not sure how long the process will take to get a Kor Ror 11. The 60 day extension would really help matters.

Looking for the list of all documents needed for a 60 days visit family extension , at Chonburi immigration

I arrived from UK with a non-O based on married to a Thai with the intention of getting a 12 month extension. However, I'm now too late to season the 400,000 baht for 2 months before my stamp expires. Is my only option the same as recently advised to someone in the same position wanting a retirement extension, ie a Covid extension before 28 July? Or am I also eligible for a visit family extension? And in either case would I be eligible to then move to the marriage extension when I have succeeded in opening a bank account? Thanks for any advice.