After the windy nationals we discovered the jib halyard had aged and started stranding very suddenly in the area that runs on the sheave when it is in use. This is almost certainly due to more extreme raking and much more rig adjusting than hitherto, added onto a very windy year. The main and spinnaker halyards were similarly suddenly much more worn. You might want to check yours out.

Ditto mine - I changed the jib halyard before the nationals and the spinnaker halyard during.

A problem not limited to Merlin Rockets this.
Years ago Harvey Churchward of the Racing Dingy Equipment Company (Sadly no longer with us though his beutifully engineered jib furlers are still around.) sourced 19X19 (Non rotating - cranes and lifts.)  very flexible stainless wire in dinghy sizes, it had no fibre cores and was swagable as well as the then more usual talurit splices it was pretty nearly everlasting even on a drum type kicker winch, which was the harshest environment known to man for wire rope.
It's still available in dinghy sizes from the Steelwire Rope Co. Riggers take note.