How often can you do a 60-day visa run in Thailand, and is a border run acceptable?

I've done a trip to KL last month (my first border run ever) once back in TH I was asked many questions by the immigration big boss in perfect english.

But I took my already filled out papers for NON O visa and then it was accepted.

IMO it's just the IO who decides to stamp or to refuse...

Currently, there are no written rules on the maximum number of entries on the visa-exempt scheme, regardless of whether entering by land, sea, or air.

But it's possible only until the officer at passport control gets doubts about you being a genuine tourist. If you keep doing border-bounce, eventually you will be pulled aside at the entry point and asked about what and how you are doing in Thailand.