There’s a weird one in Torgue’s DLC - on one of the buildings in the main crater is a vane with a unique vandalized “Fully Torgue’d” sign on it. You can’t actually jump up there, but you can get pretty close.
There is also a legit one - access to an actual red chest in Hammerlock’s DLC:
From the end of Ardorton Station (where the Fast Travel is), walk through the nearby boundary to Hunter’s Grotto. You’ll be on the stub of a broken bridge, but if you can clear the gap to the next standing bridge station, there’s a red chest there. The jump is tricky but quite possible.
It seems like there were way more, but I’m so out of touch with that game now.