Now on the 3 devices the game is running on, hp g7 laptop, usb external drive, amd 3350m/ 6620g You can get the yellow gem from the Hang ‘Em High secondary entrance you get to from the lower warp area in the center of the hub area. You can gain access to the Blacksite via a mission found on Sanctuary III after completing the main campaign
To ensure that you receive hotfixes, make sure that your system is connected to the internet when Borderlands 3 boots up and hang out on the Menu screen until you see the background change (right now