That is a good question.
IF I had to guess I would say you SHOULD go to the immigration office and cancel your current extension, then leave the country to get the new year-long, multi-entry Non-O visa from Savannakhet
BUT
Honestly I do not know if failing to cancel it at the immigration office will affect you after you come back on the new visa. I know it won't matter in Savannakhet getting the new Non-O, won't matter at the border, getting stamped in on the new Non-O for 90 days, BUT I don't know if it will cause you grief at the immigration office that you use or not.
@Amornrat *********
, do they have to cancel their current year long marriage extension from the immigration office if they're going to get a new Non-O visa in Savannakhet?