@Shai *******
no, you need to have the required days left on your current stamp when you apply for the Non-O visa to cover the 'under review' period
In Bangkok you need a minimum of 15 days to apply for an in country Non-Imm visa because it goes under review for 2 weeks. After you file the application for visa/pay the 2000baht fee they give you a receipt and it has a date of 2 weeks out stamped on when you come back
BUT
You're staying here on your current visa exempt entry.
They won't even let you apply if you don't have enough time left to cover the under review period
And in Chiang Mai you need a minimum of 15 BUSINESS DAYS (about 21 calendar days) to apply for Non-Imm visas up there