“If a boat is wide enough to get the appropriate angle for the cap shroud, then spreaders not necessary. “
Structural necessity is not the only consideration for the application of spreaders.
Mast shape and deformation can affect performance depending on conditions.
Spreaders even without a lower can help maintain better mast uniformity.
The real question is ROI ( return on investment). Does this owner need to spend $? for what return. Depends??
Different boat but from a Practical Sailor review of a Venture 21–
“Early boats, like the 1969 model that we test sailed, did not have spreaders on the upper shrouds. In windy areas, where mast pumping is a noticeable problem, retrofitting spreaders—or looking for a more suitable boat—would be a good idea. “
Best Regards