@Eric *********
your METV is valid for 6 months from the date it's issued. That is either printed on the visa sticker OR on the paper they emailed you if you have an eVISA <- and IF you have an eVisa you NEED that paper to show the validity of the visa.
During that 6 months you can enter/exit an unlimited amount of times AND as long as you meet the entry requirements in place at that time you'll get stamped in for 60 days each entry.
Most people (pre-covid shit show) routienely got 9 months out of a 6 month METV, by bouncing out and back just before the visa sticker expired getting that final 60 day entry and then extending that for 30 days for 1900baht at the immigration office.