Round Corner Plugin 90-Degree Selection

[ViggoPaulman]

Working with the Round Corner plugin. Is there a way to select only those edges whose faces form 90 degrees? I’m adding artificial bevels to produce furniture line cracks, since 2 perfectly aligned faces render seamlessly in SketchUp but I don’t need bevels in the shown parts of the screenshot, for example, only the places that form 90 degrees. Thanks for any advice in advance.