I would agree with you that conduction would dominate, but why do many of the supposed insulating pads have Aluminized coatings. I have never used a space blanket for anything other than a reflector, since I figured that, once I came into contact with it, it wouldn't do much to stop heat loss. If the reflective coating isn't that important, bubble plastic ought to be as effective as Reflectix. I don't know where to go for real world testing.