@FaheemMitha no I didn't as I didn't see a big advantage of showing yet another example (and there are many l3keys examples on the page), and the l3keys example would've been identical to the expkv-def one (modulo the different key defining syntax, and the expl3 naming conventions).
@UlrikeFischer ... and a couple of dozen confirmation queries "Are you sure?" -- "Are you really, really sure?" -- ... -- "You will hurt a lot of cute ducks if you do this!"
@AlanMunn it's sort of Catch 22: You can't teach users the good habits if you't have them. But if you teach them good habits, they freak out and not use your product.