I think that the advice is rubbish. These are normally secured on most yachts with shackles. The lines do not seem to deteriorate with UV at least not for a very long time. If they did then we would all be scrapping every line on the boat together with the sails every two years. Most of the lines on my last boat were still good after 10 years in the tropics although the genny sheets were very worn. The thing that does have to be renewed every two years is the bungy which takes up the slack on the topping lifts as it loses its elasticity. One thing you have to watch is that the lines securing the tacks are not too long. About a couple of inches above the bottom of the forestay is about right. If it is much higher the halyard will be jammed up against the sheave box at the mast head when the tension is cranked up to flatten the headsail as the wind strengthens.
