I have lived in Thailand for many years and have been using a drone in Thailand for the last few months with no problems whatsoever. I have also used it and flown in from Bangkok to China, Indonesia and Myanmar without the slightest interest of the airport authorities.
I really wouldnt advise any foreign tourists to obtain a operating license for a Mavic if you have arrived under a tourist visa. (For commercial use or even non-commercial use if you have a work visa obviously it becomes far more necessary.)
I will explain why but first you have to realize that Thai Law is written in a 'deliberately' 'opaque' way. If you look at where you are legally allowed to fly it is pretty much nowhere but it is not to stop flying but to have the power to prosecute anyone who is doing something they dont like.
Now as to why a 'foreign tourist' is potentially going to get himself in a 'lot more trouble' having a 'license' than not having a 'license'
Under the MOT announcement on drones (RPA)
https://www.caat.or.th/wp-content/uploads/2017/02/Announcement-of-the-Ministry-of-Transport.pdf you will note under Article 9 1.c and 1.d in order to qualify for a license you must have
...knowledge and skills to control the drone and...
...knowledge and understanding of rules of the air...
...pretty straight forward right
But if you use that 'knowledge' under Thai Law you are deemed to be 'working'
That might not make sense to you but under the 2008 Alien Labor Act
http://www.mol.go.th/sites/default/files/downloads/pdf/WORKING_OF_ALIEN_ACT_2551_DOE.pdf which naturally states that a foreigner cannot 'work' without a work permit it is very important to understand the definition of 'work' and under section 5 it defines work.
"Work" means engaging in work by
exerting energy or
using knowledge whether or not in consideration of wages or other benefits;
Now I am sure you all think that is a complete nonsense in terms of the definition of 'work' - how can it be 'work' if I am not being paid. But there is an absolute mass of case law to back it up. I would guess the original idea was so they could prosecute foreigners 'actually working' but being paid overseas but it has been used against say foreigners on condo management committees (which are unpaid) and even charity workers.
So seriously, as soon as you show 'someone' your 'license' that you are allowed to fly, they will likely ask to see your 'work permit'. And when you say you dont have a 'work permit', they will ask 'why you have a license if you are not working' or 'why are you working without a work permit.'
P.S. The maximum sentence for working without a work permit is 5 years in jail.