Pretty simple stepper motor mount for 2020, has some adjustability by using the slotted screw holes. Can be used in a few different orientations.
Motor screw hole slots are sized to M3. Probably a good idea to add washers.
2020 extrusion screw holes are sized to M4.
[update] tightened up the tolerances on the m3 slots and opened up the m4 screw hole.
[update] Added a 4xM4 screw mounted version with better screw positioning. ('1.2 file')
[update] Added a 2xM4 screw mounted version with hidden M4 scews. ('hidden-1.2' file)