Anyone have an answer for this?
A lot of wear on the shrouds are due to there movement (and ability to move) around the hound, shackle/s and trapeze wires. On every tack one side is loose and when you come about tightening again (sometimes quick and hard), consequently the turnbuckle ends may snag on things and over time it becomes mangled or a strand of wire will break.
Comparitively speaking, the jib is a lone ranger up front by itself with a relatively constant pressure on the wire and nothing to wear against. Certainly check it for wear, but I have never heard of one being replaced.