UPDATE:
There was an issue in the RC3 version, Prusa fixed this in RC3.1.
I changed the gcode and 3mf file here as well to this updated RC3.1 design.
This file can be used to print 8x the RC3.1 version at once on your MK3/MK2.5(s).
Print time is around 18h50min for all 8 at once including the bottom reinforcements.
PETG
30% infill
0.35 mm layer height
3 perimeters
The author remixed this model.