i still haven't made bracelets and neck lanyards for this same issue,
but have put a little more thought to it,
haven't tested anything,
went down the mental road of magnet clasps,
they are awesome but still not quite fitting the scenario,
they just aren't quite suitable,
and then i went down the crocodile clip road,
and now thinking simple paper clip,
one bend of it taken out to make an elongated c-shape (as though a staple shape, in place),
which is simple and flat and far less pricey, a range of colours and sizes,
now just have to work out how to affix the cord ends
still lacking an elegant finish.
could put a curl on the ends of the clip...