Can I enter Thailand on a visa-free entry if I have a valid Non O retired visa?

The user inquires about their ability to enter Thailand with a visa-free stamp for 30 days and subsequently extend their stay, despite holding a valid Non O retired visa. Comments suggest that while theoretically possible, regulations may require them to use the Non O visa first upon arrival, as it is already in their record. Several responses emphasize the necessity to utilize the Non O visa to avoid complications.