If 50 mg/day for 90 days is the recommended treatment for Iodine insufficiency then I don't understand why people would carry on taking 100 mg/day indefinitely. I cannot believe one's environment is THAT polluted where 100 mg/day is needed indefinitely, and besides most of that Iodine is not even absorbed. And so I find it hard to believe so much Iodine is justified as maintenance mode for eliminating halogens.
Having said all this, taking so much iodine to tackle specific issues might be warranted. To tackle a certain systemic fungus or bacteria. Some cases of PCOS and FBD might do better with so much iodine, although I am not sure of the exact mechanics as to why (..I think iodine's value goes beyond bromine/fluorine removal).
It seems that one simply doesn't know when one has reached iodine sufficiency and how much to take for maintenance once sufficiency is achieved. I'm not sure if I have much faith in iodine load testing. Perhaps the best solution is to follow the iodine doctors' guidelines and make adjustments based on the presence/absence of symptoms?
Lastly, everyone seems to be looking at iodine from different angles to achieve different things. Some here seem to take an extraordinary amount of iodine/iodide daily for years with hope of eliminating every speck of fluorine/bromine from their system. Others might find this overkill; a nominal amount of these toxins is probably harmless. Others don't give a damn what iodine does so long as it resolves thyroid, breast, prostate, or other issues. And so it is probably impossible to devise a one-size-fits-all guideline like the iodine doctors attempt to do.