I understand that when renewing the yearly extension of stay for a non-immigrant O visa based on retirement, you have to use the immigration office in the province you're registered with. Is that correct? Or can you do it elsewhere? Furthermore, what about 90 day check ins? Do you also have to do them in the same office under which you were registered?
And what if one were to move in the middle of their yearlong visa extension? Would you just register a new TM30 at the new office and then do your next yearly extension at the new office? Or would you have to visit the old office first?
TLDR : Answer Summary
When renewing a yearly extension of stay for a non-immigrant O visa based on retirement, you must do so at the immigration office in the province where you are registered. For 90-day check-ins, you also have to report at the same office that issued your extension. If you move during the year, you need to file a TM30 (and possibly a TM.28 for address change) at the new office, and your next yearly extension should also be done at the new office. Returning to the old office is not necessary unless specifically required.
90 DAY REPORTING RESOURCES / SERVICES
- Use the trusted Thailand 90 Day Reporting Service to get your in-person report done and mailed to you for as low as 375 THB (even if the online system doesn't work for you).
 - For immediate assistance, contact Thai Visa Centre directly via LINE at @ThaiVisaCentre or Email them.
 - Join the Thai Visa Advice Facebook Group to ask your questions, and get advice from others.