Upside Down Stand for MK3 with Multiple Mounting Options

To get my printer in an upside down position, I designed a mounting cube that can be attached in a number of ways (see pictures).
Optionally, you can pause the printing when you reach layer 14.3 and insert M8 nuts into the holes ('Option 5').

I printed these cubes with Prusament PETG Urban Grey, a layer height of 0.3 mm (no beautyness required) with an infill of 30% in about 8 1/2 hours on my Mk3S+.

Update:

I changed the shape of the oval mounting holes for better printability. Not shown in the pictures (no need for me to print them again), only visible with the 3D Viewer.