Hi there!
The thing with multi touch is not exactly if you can or not multi touch the buttons on screen, but also how RPG Maker handles the input process inside its code. Even if my plugins support it, some changes must be made on the input part of RPG Maker too.
What are your specific needs for multi touch? Just for curiosity ^^
I may implement it on the future, since I'm visiting a lot of my old plugins to make some changes. But it may take a while.