What is the current process for obtaining a re-entry permit while on a 60-day TR visa in Thailand?

TR-60 day... RE-ENTRY PERMIT

Hi members,

after searching many posts, I want to make sure of procedures, I'm on a single entry 60 day TR visa. Likely departing from BKK (swpmi) after only 20-25 days in Thai.

- Do I check-in for flight, then pass security with my boarding pass, then ask for re-entry permit at passport control or after at the desk ? maybe go to the far right APEC/Aircrew pp line as someone recommended?

-Anyhow, is it the same immigration desk where I see overstayers fixing up their misdemeanour, after passport control ?

Few years ago on WP, told by Thai immig. that I should go to floor 5 first and apply before check-in.

What is the current process?

Thanks in advance.