I cant really say if it’s the same for all requirements at the DLT but I’m renewing my Thai license. I was given a date of exactly 2 months for my appointment.
There’s a 2-month wait now at the DLT center in Bangkok so I hope you’re not in any hurry. My appointment is in the middle of April to renew my Thai driving license. You also need a certificate of residency either from your embassy or from the Thai immigration office in Chaeng Wattana.