The reason I ask this is because there are several different versions of the spell sniper feet, and all of them double range for ranged spells with attack rolls. Most feats that are like this specify they don't, but not spell sniper. I'm not asking how you'd rule it, I'm asking if the base rules allow it. I can't find anything on this. I'm hopeful because this would mean that a sorcerer + warlock could eventually have a range of 9600 feet with eldrich blast.
You can take each feat only once.
Unless the feat's description says otherwise. PHB page 165, second paragraph of feats.
As an example of a feat that can be taken more than once in the PHB there's Elemental Adept.
A sorcerer using the metamagic distant magic would double the range on top of the benefits of the feat, since it's not a feat taken more than once but similar effects.