To get around the issue I simply went to a 6mm washer which has a much better fit.
Alas the 1/2-13 cap screw looks even worse with its mating washer. It is the lathe to the rescue helping be convert a washer with a more appropriate OD for a better "fit"
The reworked undersized washer was next and has the best feel for me thus far so I made up 10
All of this reminds me of the fun I used to make of Sean for having to turn down all kinds of screws to meet Franks aesthetic for the Artemis Labs TA-1 The more I think of it, the more I actually feel I may be nuts.