Khaek Dam has become a bit generic 'within' Thailand, it was one of the most widely planted papayas alongside Holland. I would say that if you bought seeds from Thailand labeled as Khaek Dam and the papaya has an excellent sweet test that ripens evenly, then you have Khaek Dam. One unique thing about Khaek Dam is because of the slim profile, on hermie plants you should have 2-3 papayas hanging from each flower stem. Also Khaek Dam will take a break from for 2-3 months after a big fruit set. It grows tall immediately, but the trunk is strong, and will widen and support itself up to 30 feet tall.
However because it was so widely distributed, the authors of this article
https://www.technologychaoban.com/news-slide/article_7772 say that it has been cross pollinated and 'adapted', 'changed'.. sorry for the wrong word in translation, but to say the distributed genes now do not match the original variety. So that really when you buy Khaek Dam, to accurately know what you are growing search for varieties that are clearly labeled what they are with an adjective or province added as a suffix.
e.g. Khaek Dam Nuan แขกดำ + ดำ or shortened to แขกนวล
I have personally planted Khaek Dam Nuan, and it is really the best papaya I ever had. The slim profile allows for you to really allow this papaya to ripen to a very rich sweet red flavor similar to a ripe watermelon. This is main problem with Holland, the outer skin will rot before the inside ripeness matches the outside. With Khaek Dam you can allow to ripen first, then I add to the fridge for a day or to continue to ripen delicately. This article says Brix measured at 13.44
Khaek Dam Nuan favors male and female from seed, hermaphrodite tends to be about <30% from seed. It can handle 2 feet of rainfall overnight as long as it drains off.