Hi Martin,
You can do it with the teensy, but it would be more complicated than using a LED controller with ArtNet (like Advatek Pixelite - it's cheap and reliable). Using ArtNet will not limit the framerate, Pixelite works up to 100 FPS (if you set Max ArtNet FPS at 100 FPS in MM). It's cheap and there's one fuse on each output, which is a good thing if you have electrical issue or if you do things wrong with your cabling, like putting 220 or 110V directly on the teensy (which happened to a friend of me with teensy, hopefully it didn't got to the USB port of his MacBook...)
Anyway if you do it with teensy, it should work. Here are latest tutorial files:
http://www.madmapper.com/download/madla ... _files.zipCheers