Some feedback.
Today doing my 90 day report (thai wife) at Pak Kret, I copped a 2000 baht fine ! I understood the 90 days would restart from the date I extended my visa. Apparently not, it is a regular 90 day cycle irrespective of the visa extension between cycles. I had completed all other 90 day reports on time.
So don't assume your visa extension date restarts the clock on your 90 day report.