I thought it was weird that these could only be stored in a sim's inventory and a storage chest so I decided to fix them. They can now be stored in the following places in addition to those:
Craft Sales Table
I may add more options in the future if needed but this seems to work well for now.
May contain spoilers!
These mods are required for this content to function properly in-game. Please read through all the information on the download pages so you understand what's included with that mod and how it works.