Thaiest and another one you posted are referral sites or booking sites that make a commission. Surely, there's an official list somewhere, but the only one I've seen is that list you reposted from TATnews.

The google map is pretty good if it's accurate.

I thought the Samui+ program was overly complicated compared to Phuket Sandbox. And because of the airport ownership more complicated to get in and out. With all that nonsense, unless you really want to or need to be in Samui, not much point to it, IMO.

-David