Анонимный участник 224 One school told me that the visa would be tied only to their school. In fact, such a note happens when you do it through a specific school or through helpers, they like to tie the visa and then oblige you to buy a course, if you do everything yourself, then no obligations.
It is also desirable to be enrolled in a cooking course, but I think the border control will also accept Muay Thai. I have nothing written down, because I did soft power myself, without help from agencies