Well I discuss related issues here, but I'm not the first person to notice. Population ethicists have raised these issues many times before. I don't have any good references on hand because I learned about these issues from classes and discussions, not from reading papers; but here are some search results to get you started.
Edit: clarification
Can you give examples of time-relative interest account breaking [1] and [2], or a citation? I'm relatively ignorant of the maths here.