My non-immigrant visa based on retirement (extended once without issues) is due to be renewed by 14th May.  I have a trip to the UK planned to return on 9th May.  I then have other trips scheduled in mid June, late September and early December.  So I could each time I return get a 30 day entry stamp and not need to apply for a new non-immigrant visa until March 2025.  Is there benefit to one option rather than the other.  I appreciate I could save 7,600 THB in re-entry fees.

  

The benefits will of course be the money you can save. The down side will be that you have to do all the process for a new retirement visa later if you want it back. I would chose to keep and renew the extension, as 7-8k baht is not a major sum for leaving it uncomplicated.

Get a  12 month extension and multi reentry permit. 

Understand you cannot extend a visa, you extend your permit of stay.
The Non O visa expires, but your status remains as a Non Immigrant.
You must have Non Imm status in order to apply for 1 year permits of stay.

 

59 minutes ago, If I should die said:

So I could each time I return get a 30 day entry stamp and not need to apply for a new non-immigrant visa until March 2025.  Is there benefit to one option rather than the other. 

The problem with that plan is you'd be entering as a Tourist and that would be your Immigration status.
You'd basically have to start over again by obtaining a Non O, in order to resume applying for 1 year extensions of stay again.

Depending on the number of VE entries within a given period, you may also be questioned about repeat VE entries.

 

1 hour ago, If I should die said:

I appreciate I could save 7,600 THB in re-entry fees.

No idea how you arrived at that figure.

Personally, on return to Thailand on 9th May, I'd immediately apply to extend your stay again and purchase a multi entry permit at the same time.
You keep your Non Imm status and can exit, re-enter as many times as you like for the forthcoming year.

Extension is 1,900 BHT, ME permit 3,800 BHT = 5,700 BHT, and piece of mind.

Thank you all.  I had overlooked that the Non-O status and extension of stay were separate.

 

I shall renew on my return from UK.

 

 

2 hours ago, If I should die said:

Thank you all.  I had overlooked that the Non-O status and extension of stay were separate.

 

I shall renew on my return from UK.

 

 

I think that is your best option .