Yes it is mandatory.. You get a 2 year provisional first (up to the next birthday) then you can get a 5 year if your visa status is eligible on renewal.
They are not denied driving licenses, but as the Elite is technically a special kind of tourist visa, it is not eligible for a 'full' 5 year license, and in turn things like an IDP or the license being legal to use in the rest of asean. The 2 year licenses are a form of provisional license.
Some Elite holders have got them, but it seems a rarity and not the rules.
Was not aware of that.. The implication then is you cannot use a single entry TR as a second entry of a 2 part trip (for example coming for 1 week, going to Cambodia, coming back for 3 months.
Of course now with 60 days entry visa exempt it becomes a bit moot.