emmtee
Having RAI increases your odds of getting TED, but you can still get it even if you have a TT. My TT was 2 1/2 years ago, and I didn’t have a choice because I had a suspicious tumor that was choking me. Fortunately, it was benign and everything went perfectly – no complications. Since my TT, I’ve occasionally had some very minor TED symptoms. They aren’t obvious to anyone else. I’m in the very unusual situation of having a TSH that remained suppressed after my surgery, so I’ve actually been classified as hyperthyroid all this time. After 5 dosage reductions, my TSH is finally normal as of my recent labs. 
If you’re already experiencing some asymmetry, I don’t think I’d take any chances with RAI. It really is important, though, to find an experienced surgeon for a TT.