Have their been any examples of clothes that self-fit to the being that is wearing them like a one size fits all. This is in Disney canon
Luke fits into a Stormtrooper uniform easily even though he's noticeably smaller than the average trooper.
When WEG had the RPG license for SW, they published a story in their Adventure Journal that included a girl who put on a dress that automatically adjusted itself to make her look like she had a fuller figure.
I don't believe so-Jedi garments seem to be custom made. It isn't emphasized by any means but I imagine clothing in star wars is either mass produced or custom made for quality and style and hence probably more expensive