Helpful thread. In the past year, I've gotten into the habit of using a UPS mailbox for my lens/gear deliveries, and when buying from KEH, having them send it for customer pickup to the local Fedex Office. Never had an issue, and it totally solves for porch pirates, lack of signature, missed deliveries, etc. The UPS mailbox costs extra, but KEH delivery to a Fedex Office is a free option. Something to consider.
I purchased a non-photo item a year ago that was "lost" at a local Fedex distribution center (the last stop before delivery). The vendor sent another, and instead of investigating, said they would add it to an ongoing 'tab' with Fedex for credit to their corporate account. I was shocked that they would just regard this as a cost of doing business, vs a violation that should be investigated. Losses due to Fedex theft seem to be regarded in a similar way to retail "shrink" (i.e., shoplifting) - a cost of doing business in today's world.
Reliable, theft-free delivery to our homes may not be a realistic paradigm in our world going forward.