Same in Rayong, Immigration officer said no need to do 90 days report if possessing covid extension visa. He was pretty definite & no one has said otherwise there.
I called immigration office in Rayong a few days ago, told them i already got the covid extension till October 26 & asked if i need to come in to get stamped till end og November as per the new amnesty. The officer said it's not necessary since I already got approved or stamped the extension in my passport, no need to get a new stamp or do anything. She said it's valid automatically till November 30 or the 1 month extension starts counting only from November 1st. Here is a link from immigration website that confirm this