You just need a final balance of at least 400k on the day that you apply for a Non-O or 400k minimum for two months leading up to the application for a Non-O extension (800k if your Non-O is based on retirement/over 50).
Doing that will need care to ensure that the extension is granted on the 65k method and not the 800k again. Separate bank accounts would be ideal in such a switch.
Will you have 12 months of 65k transfers completed at the time of your application for your next extension? If you started the transfers at the start of your current extension it could be very tight and mean doing your new application right at the very end of your 12 month stamp leaving you very little recovery time for any extra documentation required.
Yes, you apply online from the country where you are located but Laos is perculiar in that you cannot pay online but go in person to pay. As I said above you attend in person to pay AFTER application.
re-entering does not get you a new 90 days on a Non-O, with a re-entry stamp you get satamped back in with the previous exit date. No re-entry permit and your Non-O is finished when you stamp out. Where is your proof?
That is not how Immigration now see the use of the Visa Exempt entry especially if you max out your stay, that could be all you'll get for quite a while, it's now risky to try to repeat.