Not much to add to this, a custom crates plugin I made privately for two servers. Releasing it simply to boost my github stats, you will not be able to use this out of the box as it's paired with my custom fork of MassiveCore which is a library plugin. However, feel free to do/use anything else. Fork it, who cares.
All contributions welcome, I was in the middle of making an in-game GUI system for configuring crates easier, but this will be a future thing if it does happen as this project is not being actively maintained by myself, as there is no issues with it, seems to function fine so.