If your UK 3.0 is still going strong then I personally would not coat and coating.
The exception to this would be Gliss ("a top-coat for all CQuartz coatings!...HYPER slick surface")
ot I would go with a spray topper (EliXir, Reload, etc.) to keep UK 3.0 slick, boosted and strong.
...but Hey, that's just MHO