These two low profile Packout bins are designed to accept the Milwaukee bit holders that come in their accessory cases. I've created two STL files that you can download and print: one small bin and one long bin.
The holders store flat in the bins and can be rotated 90° to access the bits. The bins have two rows of mounting holes, but you can't have one holder directly below another, they need to be offset by 2 or 3 holes.
In the long bin photo I show above, the 2" driver bits touch the longer drill bits, but they still lay flat enough that the lid will close.
The only issue that I've found with the bins is that they tend to scratch some material off the ends of the holders, I'm not sure if that's because I printed them in PET-G or that maybe I should have used a smaller layer size than 0.2mm, but then they'd take longer to print.
UPDATE: Here are 3D bit holders for these bins
I printed these in PET-G and used a 20% Gyroid fill because I find PET-G doesn't do well with fill patterns that overlap like grid.