The program is designed to work with angles from 90°. For sharp corners, this method does not work because the resulting circuit has a very narrow section. The program will automatically calculate the sharpest angle that a milling cutter can pass through a given gap. For example, if the cutter is 8mm and the gap is 0.01, then angles sharper than 87.1° will be ignored. If the gap is not specified, a limitation > 90° - 0.5° (angle tolerance) will be used. 

You can change the direction from which the cutter approaches the corner. Usually, the program enters the corner along the bisector of the angle. This ensures the smallest gaps between the parts. But you can set the direction of entry along one of the sides of the corner - long or short. Then the cutter will completely go beyond the corner and a characteristic "bone" will form on the rectangular window. This method of processing the corner produces more sawdust, and consumes more cutter resources and processing time. But entry along the side of the corner sometimes allows you to hide the cutter exits under the joined part. For example, entry along the long side will be useful if you make a joint of parts using the Tab-Slot program.

For corners with absolutely the same side length, selecting the processing by the long side will work as selecting the side along the X-axis.

Selecting the direction by the long or short side may not work properly if you process all corners of a part or contour at once. After forming the arc of entry into the corner, the length of the sides of the corner changes and the next corner in the order of contour bypass may already be processed in the wrong direction. In this case, cancel the processing of corners and select such corners separately, processing each corner with a separate IC command.