British passport get 60 days exemption, and you can extend it in immigration for another 30 days, they have offered me 60 days more because I have a Thai wife.
I come in 2 or 3 times a year and extend and younger immigration officers ask me why I don’t get a visa, last time I was pulled out of the queue, I’m 77, and taken to fast track where I had no problem. I have asked if there’s any problem with re entry and I’ve always been told if I fly it’s fine.