Any evidence is better than none in my opinion.  It would have been great to see a photo of where one of my missing items was 'safe dropped' - when the replacement delivery was attempted, it was carded with the notation  'could not gain access' - well really, where was the first item safe dropped then - on the street ?  Still not sufficient evidence for Aust. Post to do anything though or offer any compensation

Since I posted earlier this year that our postie will no longer safe drop (and to the best of my knowledge, no other posties that operate locally do either as I have checked with our local PO and they maintained it was no longer permitted), my local postie has told me she gets heaps of complaints, some quite rude and aggressive as you can imagine, because they won't safe drop.  Several of us in the neighbourhood offered to sign requests for her to safe drop, which we had in place with the previous postie, but she said they also were no longer permitted.   She says it's not worth their livelihood as long term posties (having been posties for some 25 years), so I have been happy to accept her word, even though I find it annoying as we live on acreage and the chances of someone stealing from my front door are next to none.

If something was left at my front door and I saw a photo of it, providing it was taken from a reasonable distance, there are plenty of items that would identify immediately it was my front porch.  And no doubt the photo would have a date and time imprint as well, so I'd know if I was home.  Granted it's not foolproof but it's certainly better than a postie's signature imo