Dedicated sorter tray for core one kit screws. 
It will spare trouble of finding the screw packs on each building step.

PLA is recommended for less warping.

I already built my core one upgrade kit, so it's not battle tested yet. Please write a review!

OpenSCAD source code is here.  https://github.com/tsukimizake/core-one-kit-screw-sorter/

I used this parts list for reference. https://www.printables.com/model/1269482-parts-list-prusa-core-one-kit-and-sorting-containe