"...if it was sent with a required signature on delivery then even in Australia they would rule you must have that signature"

That is actually incorrect. Here some Australia-based examples that have happened to me, as I only use Registered Post:

• Personalised item (useful only to buyer). Old address given (not changed upon checkout). No warning given to me. Item sent to old address. Tracking shows, 'not accepted' at address (i.e. not signed for by new residents). Tracking then shows AP 'Returned to Sender'. Item was subsequently lost by AP and no tracking back to my address was recorded. Upon investigation, item could not be found. PayPal ruled in my favour, as incorrect address was supplied by buyer. I won't go into how I did subsequently help out the buyer despite supplying wrong address and opening dispute. Item eventually showed up in my mailbox about 3 months later!
• Personalised item (useful only to buyer). Posted to address supplied. Tracking shows 'Awaiting Collection' at buyer's local PO. Buyer sent a friendly reminder by myself to pick item up from PO after 10 business days. No response. Pulled up buyer's phone number and left message. No response. Item eventually sent back to me. It was noted on parcel that reminder cards had been issued to buyer. INR case opened. PayPal ruled in my favour, as buyer is responsible for collecting item (refusal to collect or sign is not accepted as INR).