Are there limitations on the duration of the Non-O visa for those over 50 in Thailand?

Agree, I am in the process of doing my 20th extension, originally Retired now married to Thai. Every year like it or not

It's year to year.

Between often a lot of changes announced, but not all implemented.

22 year on my non o now after started in2002.

dunno where you got that number. This year was my 15th yearly extension based on being over 50 from my original 90 day Non-O

Short answer - you can extend the non O indefinitely as long as you meet the extension requirements. But even for my 10 year pensioner LTR, when it ends then it ends and then I can apply for the same or different appropriate visa at that time. If you were to end your non O you could then apply for it again at a later time.

You may be mixing some information. Whether 10 years or not depends on what visa you mean actually.

1. Non-O based on being over 50 (retirement/pensioner) single entry gives you 90 days on entry, and you can apply for a 1-year extension every year, unlimitedly as long as you meet the requirements.

2. Non-OA (so-called long-stay visa, also based on being over 50) is multiple entry and gives you 365 days (or the same as insurance validity) on entry every time for 1-year visa validity (with this you may be able to stay for nearly two years). You can apply for a 1-year extension every year, unlimitedly as long as you meet the requirements. Or you can apply for a new Non-OA again.

3. Non-OX (so-called long-stay 10-year visa, also based on being over 50) is multiple entry and gives you 5 years on the first entry, and you will be stamped until the same date on every entry for 5-year visa validity. You can apply for a 5-year extension at the end of the first 5 years. You may be able to apply for the same visa again after 10 years.

4. LTR-P (Long-term residence visa) is working similar to Non-OX. requirements and benefits are different from Non-OX.