right because you don't GET a stamp in your passport when you do a 90 day report,
It's the TM47 form and on the receipt they give you on the bottom left is the date for your next 90 day report IF you don't leave the country before hand
They seem to take EXACTLY as long as their posted processing time <- which is 15 BUSINESS days (not counting holidays and weekends)
AND
They usually wait to ask you to send every page of your passport (blank pages too) to them to check you are still in the US and haven't bailed back to thailand.
nope, when your work permit <- which is a requirement of you HAVING the extension you're on is cancelled then you have to go to the immigration office and cancel the extension AND you'll get fined for every day after the work permit was cancelled that you didn't have the extension cancelled
BUT
Seeing as you're getting a DTV (which is employment prohibited) <- meaning you can't work IN thailand for a thai entity, you're fine doing nothing,
Just go get the 5 year DTV, come back in and get the 180 day entry on it
they don't care in the least, it's not a requirement at all
he could have left with a valid work permit/extension of stay & a re-entry permit and still applied for a DTV, get it approved no issues and enter the country on it when he comes back