When should I report my 90-day requirement after receiving a new Non-OA visa extension?

You don't have a non-OA visa anymore. By saying that, you're complicating things and making your question difficult to answer.

You have a retirement extension. That's it.

The 90 day report and the extension are 2 completely different things. Some immigration officers might do a new 90 day report when you get your extension, and some will not.

If the immigration officer did not put a new 90 day report slip inside of your passport when you received your extension, then they did not do a new report for you. You would then do it 90 days after your last report or your last entry to Thailand.