Goal: Test custom components outside of the live environment
Details: I am trying to push an update to our custom component library but need to test some changes. I am worried that the changes may negatively affect the component in the live and in use environment. We have a production and development version of our app running.
If I switch the library to use my dev one
would that change only the instances in our dev environment or do we have to create a separate "clone" of our main app to test any custom component changes
Switching your library to use your dev one (as shown in your screenshot) will not automatically be set only on your dev environment. In fact, whichever version of your custom component that you choose will be used by ALL your environments.
However, you can use releases to manage what it is you want to do. You can create a new release publish it. This will remain the liver version of the app until you publish another release. Then you can work on your app and test another version of your custom component, and then create a new release and publish it when ready.
You can access releases in the sidebar, just above the settings cog: