Just a data point.

I was in the land transport office (Chiang Mai) and they were quite happy to issue a 5 year Thai driving license, providing of course the usual conditions were met (previously holding a 2 year etc) for me as a DTV holder.

Was curious how that would work out as the Elite / Privilage visa often is denied this ability. They also knew about the LTR and said they would allow a 5 year for those also.