Unions have been an easily accessible way to create complicated shapes without needing to learn how to use dedicated software such as Blender, but in the seven years since they were introduced, there hasn’t been an accessible method to manage your Unions. They don’t have a page on the Creator’s Dashboard, they can’t be inserted from the Toolbox, and you can’t change their ID from within Roblox Studio.
Right now, if you want to be able to insert Unions you’ve made in the past, you need to use the ItemConfiguration API to dig through a list of unlabeled SolidModel IDs, and add those into a .rbxmx to load them into Studio. It’s tedious, and many users don’t even know that it’s an option.
How to recover invisible / corrupt unions
Allowing developers to insert Unions easily, such as through the Toolbox, would make re-using Unions a lot more accessible. Rather than sifting through old creations, or using cumbersome API, devs would be able to reliably reuse resources they’ve previously created towards new objects and structures. This has the extra benefit of potentially cutting down on the amount of assets the game would need to load, if the dev would otherwise be creating a new Union without this feature.