Most of the players around are stacking all 4 windows on top of each other, which is easy to do with IsBoxer's window layout wizard. Of course that way you can't see if you have a legendary drop on your characters #2, #3 and #4, unless...

... you use a "DxNothing" layer with 4 mini-maps on the top right corner. See image below, I just killed a blue goblin and all the Gelatinous Spawns, so plenty of legendaries are on the ground on all characters

I can't explain "how-to" in a few lines, but you can find all explainations on Mirai's YouTube channel

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