sorry, didn't read it closely enough. so, the warm kegs are carbonated and 60ish and waiting to go into the keezer? if so, my comment stands for sure. try adding some hops in a sack to the keg and invert the keg a couple times per day for a few days. you should get a boost in hoppiness. just try it in one. you made 15G of IPA that is underhopped? shame on you! ha ha. just kidding.
hops added to carbonated beer taste different to me. you might love the flavor. some people love adding hops to the keg and serve off of the hops the entire time.
you just need a way to separate the hops from the beer before pushing through the poppet or it will clog. bag is easiest. you can also put in a floating dip tube or a beverage dip tube filter screen. if you are opening up the lid and racking off, you may or may not have luck. that is more oxidation but it could turn out ok.