Interesting. Why don't you try it out and let us know?
I have a flexible, rollable, BT keyboard that works with my iPad. It rolls up. The keys are not very deep and because it is flexible, there is not a lot of travel in the keys, so you have to press keys again sometimes. It doesn't quite feel natural. It does work, though, and it reminds me a bit of this. Mine doesn't fit over top of the ipad, though, it does on the table top. I have gone to using a regular BT keyboard.