Hi, Kat --
It is normal for some budgies to seem to be in an almost constant molt.
A couple of mine are certainly in that category.
Blue's diet sounds good and the fact that he's active, flies well, has frequent baths and natural wood perches are all very positive.
I have one budgie who sometimes frays his tail feather by the way he plays and his tail ends up rubbing against the cage bars (even though he's in a huge flight cage).
Does Blue seem to sit with his wings up against the bars of the cage where the flight feathers would rub against the bars?
I did find that frayed feathers can be a sign of deficiencies of minerals, such as calcium, zinc, selenium, manganese and magnesium.
These deficiencies may be associated with brittle, frayed feathers and itchy skin
However, Blue's condition is definitely puzzling as his other feathers all look quite shiny and healthy. :S
I'm sorry I'm not able to offer a qualified opinion on the state of his wing feathers as I've actually never seen any that have been frayed to that degree. :hug:
Hopefully one of the other members has better insight.