I'll be in Mae Sot this summer, have BKK flights arriving in late May and leaving in early August (70+ days). Does anyone have input about visa strategies?

Having been out of Thailand for a few years, I'm still figuring out the 30-day non-visa with the 90-day limit in 6 months. Namely, because I'll be right by a border, will I be able to just leave and come back a few times as long as the total time doesn't exceed 90-days?

Alternatively, are there reasons why I'd want to have a 60-day tourist visa, and/or could I get multiple entries or just cross the border to cover the few extra days I'll need?

I don't want to miss some obvious reason why one or another is a better route. Thanks in advance for any help.

You may not be allowed to board aircraft without a visa if you do not have outbound flight within 30 days so that could be a good reason to obtain a tourist visa. You are allowed up to 90 days in a six month period but you could be required to show outbound tickets within 30 days on any entry to receive a 30 day visa exempt stamp.

If you have a 60 day tourist visa, you can go to the Immigration Dept, without crossing the border, and get another 30 days.

You then fullfill your obligations for the airline.