Splitting hairs. It does not say perfectly vertical . It may mean more verticle than horizontal.
You do not have enough money to fight this, and would probably lose .
I agree with this. It wouldnt make any sense to give a specific number of degrees as a 91 or 89 degree vertical foregrip would serve the same purpose. Anything that hangs down would be considered a VFG in my opinion. Thats why theres handstops and Magpuls AFG to make it absolutely clear what they are not