I have some doubts: if I'm expecting a Bitcoin transaction, I wouldn't appreciate being told to use a third party to collect my money. The sender could instead have withdrawn the note himself, and sent an on-chain transaction to my address.
As a sender, I also wouldn't really want to rely on a third party to send funds and provide evidence. No matter how trusted your service becomes, it's never as strong as on-chain evidence. Unless you don't want an on-chain transaction trail of course.
My intention was to make it clear that Whirlwind addresses don't need to be 'initialized' in any way. if someone sends you funds through Whirlwind without you ever entering the website before you can still access them with your private key.
The sender could make an on-chain transfer to your address, but that means he would know where you withdrew your Bitcoin. If he uses Pay to Note then you are anonymous even to the sender. of course you should always know beforehand where you will be sent the funds, I wouldn't appreciate this kind of 'surprise' either.
Nothing will ever be as strong as on-chain evidence, but for the Pay to Note feature you need to rely on the Letter of Guarantee since there are no on-chain transactions being executed. We could also provide a Letter of Guarantee to the receiver which would be downloadable from the 'Dashboard' page for the first
x hours after the transaction. Do you think this would be useful in any way?