[perennate]

That is true, and there is also the point that if I copied the address incorrectly instead of the amount, it would not be recoverable. (But this is more difficult since I can copy and paste the address; I'm actually not sure why the amount can't be copied to clipboard from Checkout.js.)

Although, in this case, I was in some sense paying myself, so I would have been able to just do a reverse transaction (and eat the fees).