I have been living and working here for the past 14 years using a Non Imm B with annual extensions and a work permit.
Just wanted to update that I came back to Thailand last Thursday through Suvarnabumhi about 11.30am using a re-entry permit. No conversation with IO about anything.... Money, flight, accomodation etc. No fingerprints but did take a photo. Stamped in until Feb 2020. Queue was less than 30 minutes. So the experience was exactly the same as it has been for the last 15 years.