I've been using this grinder on almost everything not already rubbed out since I got it. It does take a little doing, but if you want a nice, even grind that beats palm-mashing, check it out.
I've tried FVF, SJF, Black XX twist rope, OGS, GLP Gaslight (post- slicing), and aged Escudo. It seems to work great for all, especially if you let it dry after grinding! I think the size is sort of in-between thin cube cut and short ribbons.
I find that the flavor and burn of FVF is somehow improved in the sense of it being smoother and more even. Plus, by grinding it first, drying is significantly faster, as Jeb pointed out. For example, the brownie of Gaslight directly out of the tin is...soggy. It's meant to be aged, but it can be smoked now. After cutting (like any plug) it's still moister than any ribbon cut out of a tin or bulk, so it's gotta sit. But it doesn't take nearly as long after it's been ground, maybe 15-20 min for my preference. It already has a crumbly texture to it due to moisture, so you're not really losing anything by grinder it further.
Others will probably malign this approach as it's sort of destroying the integrity of the flakes for expediency, but I think it goes beyond that with the way that it comes out more even flavor and burn, so that's the angle I'm approaching it from. YMMV. I figure, it's worth the $6 to try it out.