@Othmar ***
,
@Ray *********
pointed out something essential I missed.
In case you can enter on visa-exempt (1), you still have to wait to apply for Non-O in-country (3) until your current Non-OX expires because you cannot have multiple valid visas at the same time in your passport.
Possible measures, but either may or may not work:
a) ask the embassy that issued your visa to void it before you fly to Thailand again.
b) ask the IO at the entry point to void your visa.
( c) as mentioned already, enter Thailand after your visa expired)
Thank you,
@R**
,
@Oth***
, hope your plan will work smoothly. Good luck changing visas.