The best thing you can do is spend a ton of time reading, learning and then deciding exactly how you are going to use your scope when hunting big game LR. There are many valid reasons to consider FFP and ranging isn't one of them.
Are you going to dial or hold for elevation?
How about wind?
Do you measure groups with your reticle or size up game animals with your reticle?
Do you plan on shooting different power levels, especially if you also will use the reticle for elevation and/or wind holds?
All of these things will help you decide if FFP is something you should consider.
Today's FFP reticles are a zero issue for LR shooting IMO ELR is a different story. The thickest of FFP reticles only cover 2 inches at 1000 yards. So for big game applications this is a non issue for almost everyone with a modicum of good eyesight. Loosing the reticle on low powers is likely a bigger concern. However, the way the outside portion of the reticle is designed in today's FFP scopes, this is a non issue as well.
Good luck in your decision.
Scot E.