Best Practices for a Shared Derived Data Cache


I’m wondering what the best practices for using this setup would be? As background, we usually have multiple UE4 projects in our pipeline and our DDC can grow quite large in size. Would it better to use separate Derived Data Caches for each project even though there is some asset sharing between them? I’m also wondering how often the DDC should be cleaned out and rebuilt, or if that should even be necessary?

The documentation found here is pretty barebones and does not explain what the variables do:

For example, what do the following variables even do since it was my understanding that assets in the DDC would only be rebuilt if changes were made to them?
Flush=false DeleteUnused=true UnusedFileAge=19 FoldersToClean=-1 Thanks, Bill