I am on the Great Lakes and I talked to the Navtec dealer and they said that the rod itself has an almost indefinite life. Concerns are in the cold forming of the rod heads. They suggest die testing. I did this myself. The kit (3 chemicals) was something like $60 and you need a magnifier. Forming can cause tiny cracks (why you need the magnifier) in the heads. If the cracks are in
line with the rod they are not a problem (I guess could be if there a lot of them but there are not). If the cracks are at right angles to the rod (and
rig loading) that is a big problem. Rod can reheaded if there is enough length or you add a toggle.
More likely problems are with other fittings in the
rig - for example my older rod had large, aluminum(?) threaded pieces through the mast that connect the shroud mounts. If you have wire rope halyards these can cut through these pieces (used for lowers). One of mine was about 1/4 cut and I saw one from another boat that was at least 2/3 cut. If you have the same kind of mount you can unscrew one shroud and pull the other one out with the piece inside the mast to check. Not hard to do.
Also, normal precautions are needed with
turnbuckles.
Rod
rigging seems like great stuff, except for coast and difficulty handling when the mast is down (this is my first boat with it). Good luck with yours.
Bruce