Funny you mention this. We are working on support for this right now (today). EAWebKit, used by SimCity, didn't originally have Thai support, and it's being implemented now. I can tell you what it will look like though, as I just took a screenshot: http://i.imgur.com/ZFtGP87.png. It's conventional that repeated Thai decorators stick with the base glyph, though that character is invalid Thai. We might fix it nevertheless.