visa on arrival is 14 or 15 days, non-extendable whereas a visa exemption is 30 days and extendable once for another 30 days. Yep...completely the same thing 🙄
I seem to remember reading you can do the test & go if there are approved blue zone places within a 2 or 3 hour drive of your arrival location, eg Pattaya is fine if landing in BKK.
so 4 and a half months. Do you meet any of the non-immigrant visa requirements? Tourist visa plus extension will get you 90 days so as things are right now you'd need to leave after 90 days and no land borders are open.