Lots of questions, and I don't know the answers. But I woudln't consider cilantro a chelator, rather.... a mobilizer. Memory is fading cuz its been a while but there's a couple unique terpenes in it, I seem to recall C14 terpenes, which I've read are believed to be responsible.
Them synthetic chelators will move things "around" allright. Fortunately, I never took any of them. Iodine, on the other hand, appears to rapidly cause the metals to move to kidney and bowel and on out of the body, rather than permit re-deposition elsewhere.
All yer doin with iodine, is giving the body an essential nutrient it needs, that its been deprived of in most cases. Once its got enough iod, the body's normal elimination chanells are no longer inhibited as when it was deficient. i.e., the body does the job it normally wants to do, only better.