For a long time, I used percentage in Woodturner PRO but then I partnered with Jerry Bennett who makes the SegEasy Plates and is the father of the Wedgie Sled in segmented turning. He used degrees and since he is the person that makes my plates, I decided to switch to degrees in my software. Each of his plates has a set amount of degrees and so I wrote Segment PRO defaults to match the number of segments of each disk.
At that time, I switched Woodturner PRO to also measure the gap in degrees. But you need to set the number of degrees manually in that software. Each plate has the correct number of degrees of gap engraved into the plate so it is very easy to make sure you have the degrees correct if you’re going to use a SegEasy plate.