Out of curiosity: How else could the RNG store be designed
if it wanted to cover players that've played 50 hours, as well as 500+ hours ?
IMHO, there's a fairly straightforward way to keep the "RNG"-ness of the packs, "encourage" players to put time into the game while also not punishing players that have put über time into the game: don't keep maxed items in the store.
I understand that Biovar probably doesn't want people maxing out their manifest in the first 20 hours, b/c then the fun and excitement of new unlocks/challenges is gone and it quickly becomes mundane, for a lot of players. I'm fine if they want to keep the UR facet of some guns to start, but I'd run it differently.
Say on Day 1 they have 15 characters, 15 guns, 5 gears, 5 attachments for each weapon class, and 4 consumable capacity upgrades. If they want those things to be a mix of Common, Uncommon, Rare, and UR just like they currently are, I'm fine with that. This will keep people from figuring out what the new TGI/Harrier or Sexbot/Reegar OP as hell combo is and using it from day 1. There's a certain level of stagnation you get to when people can just pick and choose what kits and guns they buy and myriad options are part of what makes this game so unique and great. I don't know if you ever played Black Ops but once people have Ghost/Famas unlocked, they would sit in corners and play that same class until they prestiged, and it truly made the game frustrating and boring. Those unlocks were available very early on in the leveling process as well, which added to the problem.
What I would propose is that they don't continue to allow you to "unlock" things you've already unlocked. No more duplicate consumables that are sitting at 255, no more super userful skin tone unlocks for my Proguard (you know, the one with a giant hulking mask covering his face), none of that stuff. I'm fine with leaving a generic "common" character like you get with the 99k packs for gaining XP outside of playing, I actually think that's a good idea. As you get your unlocks, the unlock pool obviously dwindles down and therefore the UR weapons would become easier to obtain. I'd also imagine by the time a player got to that place, no one would begrudge him being "given" those last unlocks b/c clearly you've put in work at that point.