Rangefinder is a perk that has the following effect:
Aiming this weapon increases its effective range and zoom magnification. Increased projectile velocity while aiming Rocket Launchers and Grenade Launchers.
Does this perk do anything else on bows besides increase the zoom magnification? I'm unable to find any answers for this, since Bows do not have a range perk or any damage falloff seemingly, and the projectile velocity in the description states only RLs and GLs.