Thanks guys.
I see that Amazon has all kinds of lengths of cable. 10 ft. should be fine, and for the same price I can get 16 which is even better. I have never needed long cables in my studio so have no experience there.
Glad to hear that this should "just work". I was looking at the manual and (unsurprisingly) they only mention connections to windows computers (as far back as Vista). But, in the Amazon blurb they say that it'll work with windows, mac and even android.
Thanks for dissuading me about connecting via old form MIDI. It was a really dumb thought!
I'll be putting my WK-3000 in the closet for a well deserved rest. I fear its days are numbered and don't want to be key-short when I'm doing a project!