In fact, I'd recommend anyone to stick to magic boxes for now... Not because of the viewer side of the Merchant Outbox implementation, but because direct delivery simply does not work properly on the server side. It's still full of bugs and I myself reverted everything to magic boxes till everything is fixed and LL shuts the magic boxes down.
I really don't see why LL didn't stick with magic boxes. In now over 5 years of using them, I never came across a problem (there have been perhaps 5 or so delivery failures in total, but a simple "redeliver" fixed it, when the direct delivery "redeliver" feature is broken since it redelivers to the buyer and not to the recipient, meaning gifts are redelivered to the wrong person !).