The Plane tool's Pick point & Direction (Local) mode is broken.. when selecting a surface (by right clicking the surface) to project the local direction, the local projection isnt aligned correctly to the surface, it rotates slightly making the tool useless to flatten surfaces or expand an already flat surface as it will slowly diverge from the initial local direction of the surface. if you hold right click and drag over a slanted surface that is 100% planar, you will see in the Tool Options Menu that the Normal cords will shift around, this indicates that the surface isnt Planar as the Normals are changing from one point on the flat surface to the next... this only happens when a surface isnt 100% XY or Z projected, ie - a boxes surface that is rotated. The only way to currently get an aligned projection to the surface is to change your brush to something like the clay brush, hover your brush over the flat surface and press the (*) button to align your camera to the surface, than pick the "Pick point & Forward Direction" option in the Tool Options Menu and right click the surface. in the first image i uploaded, you can see the red plane is sliced in half indicating that its not local to the surface, i got this result by turning a box and res+'ing it once. the second image is how the first image should look, and in this one i aligned my camera to the surface than right clicked with the "Pick point & Forward Direction" option. i cant think of any practical reason for the local mode not working so it must be a bug, this is the newest update and i dont know how this has gone undiscovered for this long but i hope it can be resolved.