Can a single entry Tourist Visa be extended to a multiple entry visa for 10 months in Thailand?

The user inquires about the possibility of extending a single entry Tourist/Boxing Activity Visa to a multiple entry visa for a duration of 10 months. Commenters clarify that a multi-entry Tourist Visa obtained from their home country allows for almost 9 months in Thailand through planned border bounces and extensions, but the single entry visa cannot be converted to a multiple entry visa.