iTunes doesn't look at the Key tag in any case, so you'd never see it there. I can't recall offhand if Traktor uses the Key tag but if it does, it'll be necessary to "check consistency" on the tagged files after writing to them for the new tags to be read by Traktor.
I hope that answers your question; if not just hit me up at the contact address on the KF site.
As for a donation, if you're not into Paypal you could buy a couple of my dnb tunes at counterfeit.bandcamp.com. =)