You're the first person I've met who has been on PTU. When my Graves was diagnosed, I was scheduled for an unrelated surgery. It had to be postponed until after the RAI treatment. Then my levels were going down so slowly, my endocrinologist put me on PTU to try to help me get surgery-ready.
Did you have any side effects from the PTU? I had a severe problem with my sense of taste. At first food just tasted bland, then it got to the point where it had no taste or a nasty taste. That sounds like a really minor issue, but it really affected me badly.