preventing wake eddies by spiral rope?

Cool. Could not agree more about eliminating stainless.
What are you doing about luff tension on the jibs?
We have built and installed quite a few unstayed carbon masts and not had any vibration problems. So, I would tend not to worry about it unless it happens. And then, a halyard from the masthead to the bow will almost certainly bend the mast enough to eliminate the critical frequency. Wrapping anything round the mast will almost certainly increase the drag, as well as being a pain to install.
Are you building them yourself?

 

the first idea was to run the Dyneema jib halyard aft and tighten up against the upper tack fitting.
But the angles are rather acute, better than nothing I suppose.
The jibs have manually driven hoyt booms.
Still trying to imagine the space available around the buried mast stub on the keel.
The aft mast arrangement does screw up the accommodation.
Yes, rather like the idea of running the carbon uni all the way and gluing the circular halves together.

Since the intention is to lower the jibs while anchored the masts would be rather naked for a lot of the time.