Leaving HKT to SIN, have 1-year non-O. Want to avoid crowd at HKT Immi, would be great if can get the re-entry at the HKT airport or maybe the Patong office.

You can get a re-entry permit at the Patong office.

Not sure about the airport. I have seen reports they are only available there when the immigration offices are closed.

I found out the hard way that you can get a re-entry at Phuket airport. Was headed to Singapore yesterday morning and realized just before leaving home that I forgot to get a re-entry. Got to the airport and yes I got one there. Tell the immigration officer you need one and they take you to a little office and it's done in 15 minutes. Don't forget to bring a 4x6cm photo tho.