Just be aware many immigration officers get twitchy if you exceed 180 in a year. Under Thai tax laws you then become a tax resident, and they will assume you're working in the country (which you may well be, but that's another story), and could deny or restrict your entry
METV gets 60 days on each entry which can be extended a further 30 days at an immigration office. That's 90 days on each entry. If the first entry is at the commencement of the visa, and the final entry in the last day of the visa, this gives 90 days x 3 = 270 days. Won't quite work at exactly 270 as you'll not be entering on the date of issue, but the sooner the first entry after issue the longer the overall stay in the country. Requires two border bounces, but no requirement to stay out of the country longer than five minutes