Can I leave Thailand after submitting my non-immigrant O visa extension application?

Are you and your Thai wife still living together at the SAME address in Thailand ?

If you are already on an extension of stay, then you can travel outside of the country during the "under consideration" period, PROVIDED the original expiry date of the current extension of stay remains valid and you re-enter the country (with re-entry permit) before the extension expiry date passes.

Hopefully you went to the new immigration office and filed a TM30 (notification of foreigner in residence) and if needed a TM27 (change of address form) after you moved there ..

AND

Hopefully you're actually on a year extension already NOT just a 90 day Non-O visa you got in country from another province.

I say that because IF you got a Non-O visa inside the country from one immigration office you need to live there/stay there until you get the first year extension.

Most immigration offices will not issue a year extension on a 90 day Non-O visa gotten from a different province.. The process has to be started and completed at the same office usually.

Now if you're already on a year extension of stay, are just applying for a new year you should be okay, as long as you have a TM30 (& maybe a TM27) filed.

I would say you and your thai wife need to go to the immigration office where you live now, get the hand out listing the requirements, and if it's the first yearly extension from the Non-O see if you can even apply for the extension there.

When you apply for the yearly extension based on marriage to a thai, most offices give you a 30 day under consideration stamp (usually it is added to the current expiration you have now as it's the first month of the new yearly extension)

Should you need to travel out of the country during that time you'd have to buy a re-entry permit (which is valid only for that u/c stamp's validity)

You will have to coordinate your trip and any possible home visit with them when you apply for the yearly extension