According to the KL consulate, ALL Thai education visas now require a criminal record check. (Edit: added "according... consulate)
The downloadable form states that a criminal record check is only required for a degree program; that is not correct.
I drove 300 km to KL because the Thai consulate in Singapore claims not to process education visas. (Edit: Singapore only processes applications for degree programs.)
The attendant at the front gate of the Thai consulate in KL who checked my papers stated no criminal check is required; he is wrong.
The Thai attendant who processes all forms and makes the actual decisions says that a criminal record check is required as of one week ago. When I asked for clarification, he said from the Malaysian police. (I don't know if it was a factor, but I'm a Canadian who has lived in Malaysia for several years).
We were told to get the check from the police station a few hundred meters away from the consulate; that is not correct. That police station told us the check must be done at the federal police headquarters (10 km away); that is not correct.
The federal police headquarters in KL told us we must go to Putrajaya (25 km away) or do the form online. The online form includes a long list of requirements, including a letter from the embassy of your home country. Processing the form and providing a criminal record check takes 1-2 months.
I'm still navigating the bureaucracy and don't yet have a complete solution, but will likely have my plans delayed by several months because of this new requirement.
If you're applying for a Thai education visa right now, expect a high level of misinformation from the Thai consulate, the requirement for a criminal record check, and serious delays in processing time.