The general statement about "people feeling best at around 1.0" means healthy people without thyroid problems of any kind. I learned from Meep that TSH is meaningless in treatment, and also from my own experience. He and I both have suppressed TSH when our FTs don't approach anywhere near hyper levels.
I can't explain why you felt better when your free levels were at the bottom of the range, but I feel sure it isn't because your TSH was a bit higher.
I know what I
'd do if the Author would cut my dose even lower...