A Flatten command coul be very useful to make four (4) or more points to lie in the same plane.
It could work as follows:
Select three points to define a 3d plane, then continue selecting some other points (connected to the previous points). The fourth and sucesive points will get flattened against the 3d plane defined.
Useful to make plane glass and other non-twistable materials
Please take a look at the ‘Align’ function- this may do what you need..