What are the pros and cons of the self defense visa for expats in Chiang Mai?

Multi entry tourist visa might be better if you enter and exit a lot, or elite visa (best long stay option because no paperwork at all)

Ed visas are designed in a way that it is assumed you will be studying/attending classes, and maybe taking the occasional short break if you need.

has a great post about this and other options.

The way ALL the ED programs work for attending a private school (which is what Jet's hand-2-hand combat school is) is like this

You enroll, you get paperwork from the school you go to a thai consulate in another country and get a 90 day single entry ED visa. When that is running down you get more paperwork from the school and go to the immigration office for a 90 day extension. You do that for the whole course getting extensions every 90 days.

IF you need to leave the country you would have to buy a re-entry permit which lets you leave and come back during one of the 90 day extensions. Because re-entry permits are only valid for the length of an extension you would need to get a new one every 90 days if you're going to leave the country AND you would need to come back into the country before the current extension expired.

Schools are controlled by the MOE (Ministry of Education) and have a minimum hours that you must attend to keep your ED visa active.