There’s a Legendary weapon exploit you can try in Borderlands 3, but you’ll need to have the Mayhem Mode 3 modifier active.
Update: A hotfix released today has reduced the rate of Loot Tinks spawning at the Mansion and scaled down the loot drops when playing in Mayhem Mode. While you’ll still be able to get some good loot if you manage to kill one, you won’t be able to farm them anymore.
Original Story: Once you’ve completed Borderlands 3, you’ll be able to experience it on a new difficulty level: Mayhem Mode. This increases the difficulty of enemies but the rewards are much greater.
There are three levels of Mayhem Mode, though this farming technique works best on Level 3, but you won’t get very far without powerful gear.
If you head over to the Jakobs Estate on Eden-6, you’ll be able to find some Loot Tinks near the Servant’s Lift to Jakobs Manor. Go to the New-U station first, save your game then head across the bridge to fight them and keep your eye out for Hoarder Tinks.
Once defeated, remember to check their backpacks for the best loot. Some players on Reddit are claiming to find six or seven Legendary weapons at a time, so kill an enemy, loot them, quit to the main menu then load back in to start farming.
There’s a chance that Anointed weapons will drop, too, so grab a buddy and have at it.