MicrosoftHi Gregory, I'm the PM for the Advanced Query Capabilities for Directory Objects in MSGraph.
You are absolutely right that our documentation is not great, and we are fixing it. We recently added this article: Advanced query capabilities on Azure AD directory objects with a clear description, many examples and detailed property support. We are also working on updating all the other parts of the documentation that will refer to this article, but it will take some time.
Today we are requiring the developer to consciously send the ConsistencyLevel header, because we don't want to hide the fact that some responses are eventually consistent and some other are not, as it will break apps that expect read-after-write consistency.
Due to other internal implementations we are also requiring $count, and that is definitely something we want to drop in the future, but we currently have not planned the work yet.