I see the same problem.
All singletons/applications mounted at the mainsite (Api-doc, acs-lang, notification, etc) are unavailable when using the the host-node-map to redirect to a subsite. Use case: http://mydomain.nl is redirected by host-node-map to http://generaldomain.nl/subsite-mydomain. This makes http://mydomain.nl unaware of http://generaldomain.nl/ and of all its mounted packages.
Did you come up with a solution or have any idea where to correct the URL handling for this.
