@Gerard *************
A Single Entry Tourist Visa can normally be extended with 30 more days, not 60.
I think you can apply for a 60 day extension if you are family with a Thai citizen though.
But regular extensions are only 30 days.
You can do these same extensions on a Visa Exemption.
Border runs are not extending anything. You are just getting a visa exemption stamp if you are eligible and they let you back in.
And they are getting much stricter with people doing this.