It is sometimes be useful to script sorting by a field repetition other than repetition 1.
This is only currently possible (as far as I know) in table view. Once sorted a Sort script step can be added to a script and the sort will show the repeating field in the sort. However there is no other way to explicitly specify a sort by a field repetition (other than repetition1)
I would not put this as a high priority request, but it would be a useful feature and it feels like it should exist as an option, as it is in fact possible, just not easily available.
My own main use for repeating fields is for virtual list reporting and similar techniques.