You are correct about feather meal, the nitrogen is bound with a protein hard for microbes to digest being the reason it takes so long. If the feather meal is just spread on top it will take even longer before to get into the soil so microbes can work on it, so it could take all summer before benefiting from the nitrogen locked up in the stuff.

If you decide to switch to something faster Blood meal would be a better alternative. It will release it's nitrogen faster because it's easier for microbes to digest, It's water soluble so can be watered in if your using mulch, it has nearly the same amount of nitrogen and the nearly the same Nitrogen/carbon ratio as feather meal, plus it has other nutrients your plant needs. There are many other water soluble high nitrogen fertilizers on the market claiming to be organic but I can't give any recommendations because I don't do use the stuff.

I grow lots of garlic. I'm not organic but use a lot of organic matter for soil structure. Even if I grew organic I still would never use feather meal because there are better alternatives and most are free. Feather meal is 12%-14% nitrogen, 80% crude protein and the other few percent left aren't used by plants. Garlic needs more than just nitrogen and all the other macro and micro nutrients any other plant needs.

I work in organic matter in the fall, included green grass high in nitrogen, leaves and compost including a little ammonium sulfate well before soil temps drop below 50 degrees. Most microbial activity is above 50 degrees and drops to zero at 42 degrees, so I've started the decomposition of the organic matter early and in very late October when microbial activity slows to a crawl I plant my garlic. It grows some roots and everything goes to sleep for the winter. Your feather meal should of been worked into the soil in the fall.

Spring comes along and I only need to give a quick boost of nitrogen before soil temps get well above 50 using some ammonium sulfate, potassium nitrate and calcium nitrate. Every chemical fertilizer I add is used by the plant, and the same exact carbon copy of the minerals released from organic fertilizers. There is no difference what's so ever. If you want to use organic sources, when and how you use it will determine how well your plants grow.

I'm with Kevin on using blood meal over feather meal for spring feeding. If you leave your bed fallow between harvest and replant, you can dig in feather meal after harvest to start settling in. I think feather meal is probably better suited to a slower grow like tomatoes, but if that's what you got... just be wise about when you apply it and make sure you apply it according to directions.