You can also try to edit the STL file and add pads at the corners, for example 10mm diameter circles, 0.5 or so in height. It will help to reduce the stress at the corner and distribute the pull over a wider area.
I attached a picture to show a part I made, the printing pads are easy to cut away after printing, they also help to get more leverage to unstick the part from the print bed.
PanCam_PanBaseA_52.jpg


Hmmm, that image came out very small... you can see the thing here.