I have the same issue on 1.9.2. The feather value seems to be ignored when a selection is transformed. It's more noticable when the pre-selection is very small and the transformation increases it substantially. I don't know if that is intended behavior, but I made a bug report.
I also agree with @HaDAk that this workflow is needlessly roundabout. I constantly have to make a bogus pre-selection and re-enter my desired selection size for every image I want to crop. And when I missclick I have to re-enter it yet again. This should be an option that can be set before doing any selecting and the set value should be stored until changed.