First and foremost, thank you for bringing this plug-in back, it looks really handy. Sadly, it didn't work for me :/
I tried it in Kubuntu 13.04, 64-bit, using Gimp 2.8.4. The first problem: there's no preview, so it's really hard to predict how the result will be. Second: it doesn't work (at least not in my PC). I renamed it as InsaneBump.py and pasted it in my plug-in directory, I found it in the path you said (Filters>Map>Insane...), but after I opened it and clicked ok (the image was saved in a folder, both as .jpg and as .xcf), nothing happened (I checked the folder where the image was saved, no new image was created).
Thank you again.
I fixed it, please try it now