This is a difficult question, but there’s a limit to how long time you can stay and be going back to back on a tourist visa (and visa exemptions) and still be seen as a genuine tourist and not a person using tourist solutions for a long term stay in Thailand. Everything is in the discretion of the IO you’re standing in front of at the airport, but you’ve already spent quite long time as a tourist in Thailand in a shorter period of time. If you enter and maximise a new tourist visa in September again it would or could be 270 days within approximately twelve months and it’s starting getting excessive. That’s why I say it could be a turning point where you might risk to get questioned or even denied at an airport.
If you’ve stayed for 180 days in Thailand within the last 8-9 months, you could be close to a turning point as a regular tourist in Thailand for a period of time, but yes your option could be a single entry tourist visa which you could extend. For longer stay ED visa also if you plan to study and get in rolled in a school program approved by the Thai immigration. I don’t want to have any strong opinion here, but remember if you meet any difficulties you’ll almost always will manage to enter on a tourist visa by land, -unless you use the strict Poipet border in Cambodia.
You do extension at your local immigration in Thailand at 1900 baht and a single entry tourist visa is normally around $40 USD unless you apply in NZ. There’s no official limit of tourist visas, but you can’t in the end do long stays in Thailand without a long stay visa.
You don’t have visa on arrival, but you have a 30 days visa exemption, which is a free stamp upon entry. Tourist visa gives you 60 days. Both can be extended with additional 30 days at your local immigration.
There’s no magicians with a crystal ball on this site and this is still the latest update, but i can assure you that the day it eventually will happen, for sure everyone will know.
Valid six months from it’s issued at your embassy/consulate. To get 9 months you’ll have to get stamped in straight before it expires and do an extension. You cant just pick 9 months you’d like to stay.
What is a long stay visa then, Non O-A or Non O-X? All Non immigrant visas are long stay visa, also the 90 days Non O visa and extension of stay (which not is a visa).