A couple of years back, at Kite Party, Laura pulled out her Zen on a very light wind day. The ferrule had come loose and rendered the kite useless.
She had paid for a ticket to travel across the US, paid for a number of nights in a very nice motel, paid for her meals, even paid for the darn Zen ... but, because of a simple loose ferrule, all that money was wasted on that morning. Epoxy is not overkill ...
I'd even coach you to go further: 1) remove the dried glue from the ferrule and sand the glued half to increase bondage ... then degrease with a solvent 2) clean the inside of the rod (tube) with a roll of sandpaper or a gun cleaning brush ... then degrease with a solvent 3) apply a thin coat of epoxy to the inside of the rod and the sanded end of the ferrule 4) insert the ferrule, twisting it slowly as you insert it to about a quarter inch from the correct depth, clean off the excess epoxy and then insert it to the correct depth ... then tape the ferrule in place until the epoxy dries. When done like this, I've yet to have one come loose.