Interesting that hardly anybody has mentioned the 16mm Sony driver on the EX1000 needs burn-in at all. The EX1000 thread was started 13 months ago and is 173 pages long.
Even if what what you said was true --and you'll excuse for being very sceptical of such claims-- I'd still strongly encourage people to listen to their sets right from the start, so that at least they can tell whether burn-in is real, or at least real to their ears. In my experience, what people call burn-in isn't really so but something else, but I DO NOT want start a debate on whether burn-in is real or not.
You can of course listen once at the start for reference, but full brain burn-in from such a peculiar signature would require progressive sessions to take place, so it's more than that (I don't deny brain adaptation but it takes time to occur).
As a material scientist, I do believe that burn-in of dynamic driver is theoritically possible (due to their cellulosic nature, which is delicate and sensitive to environment) while burn-in of armature-based drivers is unlikely (due to their metallic nature, making their properties pretty stable in usual environments).
Can't comment on the EX1000 though, I would have to try them first.