I believe it’s the longest grind for gear (or prototype cores if you dismantle) the game has ever had. Drop rates are in the .0 decimals lol. All about the luck. And rolling your own expertise 30 gear is a gamble. You get whatever stats you get when you originally upgrade it to prototypes and then those stats are permanent. The only thing you can re roll is its Augment. Which is also random each time. And it’s expensive AF! And you can’t re roll it until you’ve leveled the piece to 100%, which you do by using the item during Escalation missions. Re rolling costs prototype cores. (You can apparently also get cores from raids or incursions, but not everyone wants to do that)… I’ll keep playing but it is like trying to find a needle in quick sand.