Implement a toggle in the File View window that when enabled, only parent collections are listed, not every individual collection in the scene, which would make appending to another project file easier

Another user posted the following bug report, whereby appended collections (with subcollections) from another file will seemingly create duplicate collections of the subcollections as parent collections in the outliner of the destination project. The response from a dev was that this was/is intended behaviour and if the user wanted to append parent collections (with sub collections), that they should select only the parent collections in the File View. The report was closed. appending nested collections (at the same time) bugged?

The problem is, if you delete the seemingly duplicated sub collections, which are listed twice now, it also deletes the other appended child collections, whose structure was honoured correctly. If so, the user either won't notice it, or they have to delete or undo everything, and then re-append tediously.

I see no reason why users should memorize or tediously and methodically select only parent collections in the File View (which would mean also having the previous file open in another window and looking between both windows to make sure that only parents are selected), when there could be many parent and child collections mixed together in the list. Otherwise, the File View should distinguish between parent and child collections some other way, ie., heirarchical lines or staircase spacing, not unlike those found in the Outliner.