A couple more features I'd like to see in KISSlicer are:
1. Retract while wiping. Both Slic3r and Simplify3D have this and at least in Simplify3D (the one I tried) it really helps to reduce the visibility of the seam.
2. Avoiding perimeters. This will be really helpful at eliminating specks of the wrong color appearing on the perimeter of prints with multi-color dual extruders. Simplify3D attempts to implement this, but all they do is reduce crossing perimeters, not completely eliminate it. Maybe KISSlicer could have a slider with a % value in cases where long convoluted paths would be part of process.