I just bottled a Mesa Luna White about 3 months ago and everyone loves it, including my wife who is very picky about whites. She will only drink bone-dry whites (when she does) but loves this one. The F-pack adds more body and flavor than sweetness, but does add some.
When the time comes to add the F-pack, take a large sample sample and try it dry, then add a teaspoon or so of the F-pack to get a feel for how it changes the flavor. You could add all, half or none to suit your personal taste. IMHO I like dry wines too but added the whole F-pack. You won't be disappointed with this wine.