Inherit a folder/document set from a non-folder content type (or vice versa)

Question

I have to build a Firmware repository of some sort out of a Document Library.

I have several types of uploads there and I am planning to use document sets to group files belonging to the same firmware (sources, builds, documentation etc).

I need to create a content type hierarchy and want to have a common ancestor/root called, for instance "Firmware Repo Root Content Type". Then I want to inherit "Firmware Repo Document Set" and "Firmware Repo Document".

However, I can't find a way to make an inherited content type a folder. Will I have to deal with two roots in my hierarchy ("Firmware Repo Document Set extends Document Set" and "Firmware Repo Document extends Document")? Or there is a way?

The tools at my disposal are Sharepoint Online web UI and MS Flow. No .NET/etc. P.S. If there is a better way to implement my design - feel free to suggest direct, I need a working repository first of all. But it has to be in SharePoint - don't ask my management why.. :)

Many thanks!

Answer 1

Yes, you will indeed need the two roots! A content type hierarchy in SharePoint can only inherit from one base content type.