A 4x4x5 Gridfinity organizer for my set of Neitra setup blocks (amazon.com/gp/product/B0C1NVK1N9/). I designed this around my set, but it should work for any setup blocks 5.5" long.  The ¾" block sticks out a little farther than the others to save on material vs. using a deeper holder.  

The slots have 0.02" tolerances which worked great printed in Prusament on my Prusa Mini with 0.4mm nozzle and the default 0.25mm draft mode in Prusa Slicer.

Edit: I've uploaded a second version of the file that uses 0.04" tolerances.  I removed the original version, since I noticed my blocks are extra snug now that it's gotten cold out.