Does a multiple re-entry permit carry over to a year-long visa extension in Thailand?

Re-entry permit question -

If you buy a multi Re-entry permit at Bkk airport does it carry over when you make a year long extension?

Or is it only valid for the current visa you hold? My husband has a 90 day single entry non b. He has to leave the country before making his year long extension. But we plan on taking many international trips throughout the year. Should he buy a multi Re-entry permit now? Or buy a single Re-entry permit for this trip and then buy a multi Re-entry permit once he makes his year long extension?

Maybe this is a stupid question but I’m confused how to go about it and don’t want to buy a multi Re-entry now to have to buy another when his extension is processed. Thank you