@Vin ********
That’s not really 100% how a Non-Imm-O/A visa works
The visa has a validity of ONE YEAR from the date it is issued.
The visa comes with a multi re-entry permit included, which is valid for the duration of the visa validity
*** when you enter, you will get stamped in for 365 days
Now, given you waited 4 weeks after the visa got issued, before you flew to Thailand, the remaining visa validity will be 11 months from the day you entered, and the remaining validity of the multi re-entry permit will also be only 11 months.
*** if you fail to exit and re-enter before the visa validity expires, you can only stay until the date that you got stamped upon the entry
You only get stamped into the “second year stay permit” of a Non-O/A visa, if you exit and re-enter before the visa expires, but you won’t have a re-entry permit any more after the expiry of the visa validity