There is no change of address - so nothing new to report. You just say - No Change. I have done this many times. It is always good to have the Rent Agreement document with you in case they insist. You report change of address - new address.... not straying at the same address.
I believe you just have to take an original of your Rental Agreement in Thai signed by your Landlord. Take a copy to leave. Your landlord should have filed a TM 30. But depending on where you report the policy enforcement will vary.
The second year of the O-A operates a little differently - you still report every 90 days but if you leave Thailand you have to purchase a Reentry Permit at Immigration
You don't apply - just before expiry of the first year of the Non O-A you Exit and Reenter just a few days before that Expiry and you are stamped back in with 12 months yet to go before the new expiry.
Mic Thai MicThai Guy - pat yourself on the back - you have done better 'first time' than a whole lot of guys before you... Obviously you did your homework... Now you are on your way - in a few years to become an 'expert' like us... hahahahah