Hi Rita,
In those of us with genetic susceptibility to Graves' disease, iodine in amounts greater than 150 mcg worsens our condition and increases thyroid antibody production. Iodine, in this sense, is a trigger for autoimmune thyroid disease. Since you're already getting iodine in your diet I wouldn't add more.
Copper can be helpful in active hyperthyroidism. The balance between zinc and copper is very important and in hyperthyroidism zinc becomes higher than it should. In hypothyroidism copper levels rise. We normally have 8 times as much zinc as copper and this is the amount found in multivitamins. You'd be better off adding slightly more zinc than copper if you're going to address this imbalance. Block and replace is the easiest approach or you could stay on your low dose of PTU and avoid environmental triggers. Best, Elaine