Prefs > Scale - edit order?

Having added a lot of custom metric scales and deleted all of the imperial ones, it should be easy to drag the scales into an order eg ascending, descending to make them easy to select, but it seems I can’t. Such a simple thing but it would make life just that little easier. In addition, why can’t I edit the actual text? I have two different formats eg 1mm:10mm and 1 mm = 25 mm.