I agree that manure and blood will quickly release their nitrogen however, feathers decompose slowly and require microbial digestion to release the nitrogen bound in it. Feathers and feather meal are both considered slow release
Feathers can be added to compost with out worry. Feather meal is sold as an organic amendment. They are ground to accelerate their decomposition so obviously the unground feathers would break down slowly but with a good active pile it wont take too long.
You don't need to go through the effort of vermicomposting the frass. The n-p-k of the frass is 2-2-2 and readily available bit the biggest reward is the 16% chitin is the best part