pacifica ,If your fig is not a rare very expensive variety,get rid of the tree,
if the tree is very rare and expensive cut it down to soil level in the Spring,and it might just grow a new much healthier,and will not show the FMV on the fruits anymore,only on leaves,here and there.
Sometimes it works and sometime it does not.
My Ischia Black,(10 years old)had a bad case of Fig disease,(on leaves only tho),and after was killed ,a couple of times by Winter cold,( being planted in ground), I have to recognize,that the plant,is much healthier now.
Ischia Black is rare and ,makes delicious fruits,so i really did not have the heart to discard,and so I planted it a little farther from other trees i have.
So far so good,it is 4 foot tall this Summer,and have a dozen fruits ,plus it had a couple of Breba.Of course it will never be Malta Black,and make a hundred or more ripe fruits every each year.
So fig affected by FMV,do not have an abundant harvest,and that is a fact.
And one more thing: Do not buy fig trees during Summer,from climates where Acaria fici is present,and also ,make sure you buy dormant plants,from those climates,and only bare rooted ,,because ,acaria fici winter in potting soil at base of tree,and if you buy a potted tree from such climates, next Summer,they will multiply in your garden,and spread the FMV,from the diseased tree to the rest of your trees.
By the end of Summer Season,all your trees will be infected,and next Winter the Acaria fici dies but your orchard is totally infected,and will stay that way.
Happy gardening