NO The reticle cross hairs on a viper pst are .18 MOA at all mag . @ 1000yds that is a little under 2" . So a 12" target you would still see 10" of it or 5" on each side of the cross hairs . The problem comes when your at a low magnification at long range both the target and the reticle look small . The reticle is still only covering that 2" area but your eye will have a harder time seeing it .
Check out the second video I posted above from time 2:30 to 3:40 you will see how the reticle is the same proportional size to the target 200+ yards away At both max and min magnifications
The reticle grows with increased magnification on FFP scopes.
The video states "one advantage to the SFP design is that the reticle will stay relatively thin at high magnifications"
So, even if it does not cover the target, it seems that it would cover more of the target than a SFP reticle.
http://www.vortexoptics.com/video/first_vs_second_focal_plane