I have successfully configured Files Connect for SharePoint Online many times, and it works well for browsing and sharing files via Chatter or in the Files tab.  Next, I'd like to configure the External Object created by my Files Connect data source with a Lookup relationship to an opportunity.  I'm intending for users to be able to view files which are related to an Opportunity as a related list, on the details page for an Opportunity.  Thus far, I've not been successful.  

Has anyone accomplished this?  It appears that Files Connect: SharePoint Online is ignoring the metadata fields that I added to my document library in SharePoint.

Initially, I performed the following steps:
- Added a text column to my SharePoint document library called OpportunityId.
- Added a Lookup Relationship to the items_Files_Connect external object in Salesforce, I specified the External Column Name as OpportunityId.
- I added a few documents to my document library in SharePoint and set the OpportunityId value equal to the 18 digit id for a test opportunity.
- I viewed my test Opportunity, but the items_Files_Connect related list is empty.

To debug, I performed the following:
- Added a Text column to my external list called OpportunityId and set the External Column Name as OpportunityId.
- Created a tab for the external object items_Files_Connect and navigated to that tab.
- Modified the view for items_Files_Connect to include the new OpportunityId text column.
- I found that the OpportunityId text column is always empty. 

My debug steps lead me to think that Files Connect is not reading additional fields from SharePoint and thus that is the reason that my initial attempt to create a lookup relationship did not succeed.

I saw in the release notes (http://releasenotes.docs.salesforce.com/en-us/summer15/release-notes/rn_chatter_files_connect_lookup.htm) that Lookup Relationships should be working, but "Files Connect: SharePoint Online" wasn't called out specificially.

Appreciate any tips or confirmation if others have been able to retrieve metadata when using "Files Connect: SharePoint Online" or if you've been able to establish a lookup relationship where the 18 digit object id was stored as a field in SharePoint.