I played around with this about a week ago and ran into some serious problems where Helene would actually alter the PHP code, sometimes randomly stripping out $ marks from variables, etc.
I suspect that once they finish the code refactor these sorts of buried "features" will disappear; by their own admission right now it still needs some work. It’s a really, really cool piece of coding, though.
Also, just as an aside, FTF only highlights code. FTE edits it, but is a commerical product that costs $100 per domain.