If I have airfare purchased out of Thailand on a date greater than 30 days from when I arrive at the border from Cambodia.... Will they accept me on a 30 day visa exemption if I tell them I intend to extend 30 days at the nearest immigration office.
TLDR : Answer Summary
The post discusses the acceptance of entry into Thailand with a 30-day visa exemption while holding an onward flight ticket purchased for a date beyond 30 days. Comments suggest that passport control might not ask for proof of onward travel, though it's advisable to be prepared with evidence of funds and accommodation.