Hi Jeremy,
I haven't seen any evidence that night shift work affects TSI production, and I can't imagine that it would. I developed Graves' disease when I worked days and it wasn't affected when I later worked the night shift. It's important though to get adequate rest for general health.
When TSH is low and thyroid hormone levels are normal and you have TSI, you have what's called subclinical Graves' disease. This condition isn't usually treated although it's monitored with blood tests for thyroid function every few months. If symptoms are present beta blockers are often used to reduce them. Often, subclinical disorders resolve on their own especially when environmental triggers such as excess dietary iodine are avoided. Best, elaine