It'll take....A LONG TIME with your engies..(untill you ve them)
if you can, level those engies on a lower level ship, like fuso/nagato untill their lv 80,
so they can have more xp, while your BO gets less.
btw, I found a old screenshot when I first got my yamato...before BB34AA patch...
yea...elite bve engies with 90 vets at lv 83-85(or somthing like that)...