Texture compression is not reliable. I've already sat through 10+ minutes of conversion on this scene, and now it's doing it all over again.
Please start testing Octane with production scenes. When is someone most likely to use compressed textures? When you have a scene with gig's of textures that won't fit into GPU memory. Not with three spheres, a cube and a teapot.
If compression was happening on individual files, rather than some obscure, massive cache file, it would be more robust. Furthermore, everyone who touches the scene wouldn't have to sit through the same delays.