@Michael **********
Ah, okay.
You plan to enter on a 90-days single entry Non-Imm-O visa, and use it for a holiday of 90 days. Then you plan to do a border-bounce, to get stamped in for 60 more days upon re-entry
*** I would say your plan is okay and will work, as long as the Immigration officer at the border likes your past entry-stamp history of the recent 365-days, most of all when he doesnโt find โtoo manyโ visa-exempt entries and touristic entries
Regardless of all - be prepared to be asked for the three famous proofs:
*Cash equivalent of 20,000 THB
*a few nights of a booked accommodation
*Proof of onward travel leaving Thailand within these visa-exempt 60 days
Safe trip and a nice holiday!