You could always do what Jen Spry suggested – fit a keyring to the eyelets in the bins and non-locking carabiners to the harness. You could also fit non-locking carabiners to your existing strap. When you want to switch from harness to strap, simply unclip the bins from the harness, and clip the carabiners on your straps to the keyrings on the bins.
As for me, I’ll stick to my neck strap for the moment…
Paul Dodd Docklands, Victoria