You won’t have a problem if you’re a genuine tourist.

Landed at Suvarnabhumi from Cambodia 2 days ago. I have a Non O extension so knew I would not have problems but my mate is here on holiday. He’s been in and out of Thailand a few times during the past 12 months but always stayed inside his 60 day entitlement. He arrived in Thailand 2 weeks ago on yet another 60 day and then we exited to visit Angkor Wat in Siem Reap. Flew back in and all he was asked was, when he was leaving Thailand again. He gave a date within 60 days, didn’t have to show any proof and was stamped in. All good if you don’t abuse the system.