I don't know anything about BL. I'll try to throw out three different dramas that have themes you see frequently:
Gasohug - a short, sweet Thai series. A romance between a city girl and a country boy. Deals a bit with discrimination.
Khaen Rak Salap Chata - Fantasy body swap drama with some action/gangster scenes. I'm a fan of the actress playing the female lead. I thought there was good chemistry (but she makes anything work).
Kleun Cheewit - Thai dramas often have revenge and slap/kiss stuff. This is probably one of the better ones. And it's also "lighter" in some ways which says a lot about the treatment of women on screen and maybe within the country of Thailand as well.
I know I said three but before I cut it off I'll add one suggestion that's not a TV show. Thai channels/production companies often do series of shows. The different shows loosely tie together (so the leads are often supporting casts to the other shows within the series).
An example, the U-Prince series: https://mydramalist.com/search?q=u-prince&adv=titles&so=rated
Simple stories in 6-10 episodes that last ~60 minutes per episode. It's always a young man and a young woman finding love with different backstories. The U-Prince series focused more on university students but branched out slightly from that.
