Should work similar to using Titanium to put your internet data for an app on the sd-ext storage. Probably works exactly the same way, except that you have to figure it out yourself instead of having it automated.
Works great for TB... on apps I don't use often with sloppy internet/external storage, it's nice to be able to not worry about 80 megs of my internal storage getting sucked away just because of a irregular convenience app.