All should print nicely with default settings. I printed with 0.2mm layer height on PETG, everything without supports. However, the crossbars on the side of the base stand would have done better with support since it was not stiff enough without and started to wiggle a bit close to the top, which is why it looks like there was a slight layer shift on the layer where this fuses again with the back.

Note, on a Prusa MK3*/4 the backplane fills up the print bed completely, meaning you must turn the skirt off to print that part with that print bed size.

There are 3x17=51 positions to attach the clips to. Print as many clips as you want to hang things and put them at the locations you desire.

Find the sources at https://github.com/schiele/3dmodels (jewelry.scad).

Update: Added STL files to fit the Prusa MINI print bed when skirt is turned off. Also changed the side to print without the hole to increase stability.