My thinking was to have the Fiber-Fix for a quick "roadside" repair, then get down to taking the cassette off and using real spokes in "camp" or having gotten to a bike shop, though I do see your point as to it being a double fix (belt and suspenders?)
I've never used a cracker, so probably once I get proficient with it I wouldn't need the fiber-fix...
Makes sense. I hope you can find them there.