It looks like you are using the ngrx/data feature to manage your list of reports. That package works well for simple REST operations. What I would do is create another store for selectedForReports, since this functionality is outside of the functionality that the entity data package provides.

So, use your forReports store that uses ngrx/data to handle the query, get, update, and delete operations for the forReports, and then create another regular store to handle the selectedForReports actions and state.

Checkout the docs for additionalCollectionState. They basically require you to setup new reducers and result handlers when you use this property, it's not much different than setting up another store. Why not just avoid the complexity of this and just set up a separate store for selectedForReports?