Can I extend my 30-day visa exemption in Thailand if my passport expires within 6 months from the extended date?

Visa extension question:

I'm in Thailand on a 30 day visa exemption visit and want to make sure: Can I extend another 30 days at an immigration office as long as my passport expires more than 6 months from the Extention date? Or would I be denied if my passport expires less than 6 months from the ending date of my stay? (to clarify, my passport expires more than 6 months after the extension date but less than 6 months after the ending date if it's extended another 30 days)

Also is my exemption extended 30 days from the last day no matter when I extend it? Or is it only extended 30 days from the date I apply for the extension at the immigration office? (In which case I should go to the immigration on the last day of my exemption for the longest possible extension?)

Thank you very much for the help, it's difficult to get in touch with Thai immigration and get answers in English... I appreciate your knowledge.