Re entry permit at Suvarnabuhmi
Word of warning that the staff at the re-entry boot doesn't necesarilly fully understand the "being under consideration" stamp you get for an in country extension.
Since I had a multiple re-entry permit till 28 jan on my old extension, they did not want to give me a re-entry permit since I am flying back to Thailand on the 24th of jan. However, I need to be back at immigration only at 11 feb to (likely) get my 1 year extension.
I asked again at the immigration office just past passport control and they said I had to redo the extension request. Luckily I did not fly out before I got the re-entry permit, but basically had to beg and convince officers for the re-entry permit.
TLDR : Answer Summary
The re-entry permit process at Suvarnabhumi can be complicated for individuals with an 'under consideration' stamp for visa extensions. Travelers may encounter issues obtaining a re-entry permit if their current extension is still being processed, as airport staff may not be familiar with this status. It is advisable to secure the re-entry permit before leaving Thailand to avoid complications.