You know how some models wrap on a long print, because their angles are 90 degrees or sharper? One way to combat it would be to use rounded cubes in models. Unfortunately it is not an option for STLs. Here is a simple utility that you can load as modifier and place in the straight corner.
Set fill to 0, perimeters to 0. Slice, move it around to have a smoother curve.

P.S. You can also play with scaling the modifier depending on your model.

Category: 3D Printer Accessories