The STV makes it possible to stay 3 times 90 days, but has more requirements. This visa can not be changed or extended after these 270 days.
The land borders are still closed for tourism, be aware because the METV let you stay for 60 days and possible one time extension of 30 days based on tourism.
Why not a long time visa that fits your purpose of travel back home?
The visa gives you 90 days of stay, after that you can apply for the 1 year Extension of Stay based on employment in Thailand. You need to meet the requirements like having a work permit, paying tax and social security.
We try to help and inform people, please if you are that good in translating and know all the ins and outs of Immigration, help us in stead of telling us you knew it all before we do.