I don't trust PFF all that much let alone their college graders. But I'll be very surprised if Fannin has issues blocking in the NFL because half that projection is willingness and he's willing. Haven't watched all his games, as finding small college film is rough. But to me I think his blocking as a negative has been overplayed a bit by draft evaluators.
As it pertains to concerns with us taking him I think the bigger question would be whether he's up to snuff in elusiveness we have grown accustomed to with Kupp, and the contested catch side of things. Can he be that guy for us. I'd say there are other better fits, but he has the look of a McVay type at that position, and again I love high volume players because some guys just end up being important for numerous reasons, and whatever those are he has them.