Hi Jon. I have had FMV infected trees and uninfected trees within a few feet of each other for almost 10 years now.
Some varieties are clearly more vulnerable to FMV, showing symptoms in leaves and slower growth.
But do you thnk that all figs today have been exposed to FMV, but only some show symptoms?
Our LSU and White Hybrid, for example, have never shown any sign of FMV, and grow very fast, fruit very strong, even though there is a clearly infected tree right between them for almost a decade.
Best wishes.
John