Is it possible to snap a forcefield to a given vertex ? I want to assign different forcefields to different vertices of a cube so that if the cube moves, the forcefields move with it, but I don't know if it can be done...
Take some Mesh, Snap Faces, Parent, Apply forces separately
Take a beveled cube or some mesh you choose and parent to an empty. Create 6 new mesh planes. (Alternatively you can duplicate faces and separate.) So now we have six plane meshes in the locations of a cube and the empty. Snap the separate planes to the beveled vertices as indicated in the image. Parent the empty to the six child planes. Not shown. The empty controls the six planes. Animate the empty. Each of the 6 separate planes can have a distinct force attached by you. Estimated time with practice 8 minutes or less. Please inspect and improve this proposed answer.
You may get a shape that suits the effort by taking the standard cube in Edit Mode and Beveling the vertices. Image above.
Snapping a face and changing the object rotation if that suits you.
Plane and Triangle Snapped to corner faces. Image above.
This may have the same result of your idea with vertices. There are 33 ways to do things in Blender. This method seems reasonably simple.
Four Planes snapped to corner faces. Image above. Two forces enabled. Please excuse the busy screen capture. Part of the point is to show axis if that suits the effort.
Snapping. A random video ... please choose a better one. https://youtu.be/Sl_Otq4C9UU