Yes my entry history isn’t perfect but as you say it’s down to the immigration officer
Bit of advice try to find a immigration booth where there are officers with a few bands on their Epaulettes (shoulders) means they abit more relaxed about using their discretion it’s the rookie officers who get a bit nervous 👍
Just have a copy of an outbound flight ready in your hand within the 30 days visa period expidia let you purchase and cancel without any costs involved
Show this to any over zealous immigration officer and maybe have a recent ATM slip handy proving you have funds and you will definitely be okay
I recently got pulled over entering Suvarnabhumi airport after my T/R visa and 30 day extension ran out
Like your thinking now I went to Danang for a few days and re- entered on a visa exemption but the immigration officer called over the supervisor and after a few minutes pleading he said okay this time 30 days no more tourist visa for 6 months and advised me to get a Non O visa next time