Can I apply for a 30-day extension of my METV in Thailand before it expires?

The way I see it is if your visa expires on 2 June, after that date technically you're on overstay, but because of the amnesty all overstays are waived until July 31. Unless there are further waivers introduced on or before that date, I would think you would need to be looking for a way out, either back to your home country or to a neighbouring country to obtain a new visa. As the visa will have expired all a border bounce (assuming their open) will get you is a 30-day visa exemption, which might be denied you because of the length of time you've already been in the country. It's a lot of 'mights' because realistically no-one knows at this stage.

No one knows right now. Some say if you go on the amnesty then you have to leave Thailand and you may not be able to get any more visas for a period of time. Others say you can leave and bounce back in. Basically, keep an eye to see what gets announced nearer the end of the amnesty as anything before that is pure speculation.

If things get better and borders open up they can end the amnesty before July 31. I read on Thai advice that they might not allow extensions after July 31st for people without proper visas but who knows. Anything can happen and change within a day. Best bet is to wait and check the news frequently.

My 6 month METV ends May 17th and right now no borders are open for me to extend till August so I might just head home July 31st.

Also if they do open up borders to travel out of Thailand, you won’t know what new requirements they want for you to enter back. Hopefully things get better and I’ll visit again sometime next year

I’m thinking once the visa has expired it’s expired...after all the Covid restrictions are over you can reapply for a new 6 month METV...or I could be wrong and they might give you an additional 60 days stamp on your visa...nobody really knows at this time