One of my favorite addons, much more handy and faster allows you to cut polygons than the default Blender knife. Quickly fixed the bug after I created an issue on github.
Out of wishes - it would be good to add a option in preferences to disable switching the half-knife to the default knife when it is outside the polygons, this often gets in the way, I had to disable it myself through code in python file.
I added a new option in the latest update, a new keymap property called "Cut with preview from void", this allows you to turn on and off the preview when cutting from outside of a polygon.
Half Knife
One of my favorite addons, much more handy and faster allows you to cut polygons than the default Blender knife. Quickly fixed the bug after I created an issue on github. Out of wishes - it would be good to add a option in preferences to disable switching the half-knife to the default knife when it is outside the polygons, this often gets in the way, I had to disable it myself through code in python file.