Odd shrouds

[JohnV]

Hello--
I have an Alajuela 33 cutter that has rigging components that I'm not familiar with: below the 5/16" upper shrouds are smaller shrouds of 1/8" 1x19 wire. They extend
from several feet below the upper tangs to about the middle of each
spreader--more or less parallel to the uppers.
The only reference I could find is in Hiscock's fold-out drawing in
Cruising Under Sail, and he calls them 'cap shrouds' but doesn't
explain them, nor could I find them in The Rigger's Apprentice.The rigging instructions original to the boat don't mention them.
I posted the question on the Alajuelaboats Google group and got varying opinions as to their use and value. In fact, one poster said Mr. Toss had done their rigging and discarded them as unnecessary.
Others believed they were to support the weight of crew climbing the mast, or preserve the shroud/spreader angle. I wondered if they are to counteract any unplanned downward pull on a pennant halyard--of which there are two on this boat.
Does anyone know the rationale for these, and the proper way to set them up?
Thanks for any info.
John V