I remixed this from Malolo and Haz1's ideas for a frame mount for the RasPi right above the Einsy board. There was a Raspi 4 model, but not a 3B, so I snipped and clipped them together :)
You can mount it using an M3x10 screw from the spares bag, if you still have any. Just make sure you put the M3n nuts in the frame or the screws will poke through too much and won't allow full range for the Z axis to travel.
The author remixed this model.