@ralph.van.etten: No we did not end up doing it, but if we do we will post here for sure.

Sure. But since that will likely be a simple patch and not an extension then we could simply add a ref to this ticket in the community_resources wiki page when the patch is ready. Unless its possible to implement a phabricator extension for UI JavaScript code but I dunno since we haven't looked into this yet.

@philippe.jadin: it's funny you suggest that as we had a very similar idea as you yesterday. We are are in the process of moving from Trac to Phabricator and have that same need for client-restricted projects. As an interim solution until namespaces or something similar is in place, we are planning to implement a small JavaScript patch in our local phabricator to do something similar to what you suggest here.