Hist Tag Level Security - not respected in RTIP?

I have enabled Tag-Level security on a few tags in Historian. Historian tools (Admistrator, Excel) do seem to work properly--- i.e. viewing the tagnames themselves, and viewing data for those tags is limited to only the users in the appropriate groups.
However, in RTIP I cannot seem to get that level of security to be respected. Any user seems to be able to see the tags and view the data.
I have a case started with Support, but thought I would post here (and also in the Historian Forum) to see if anyone has successfully implemented a similar setup.
Settings in RTIP: Historian Connection uses wide open connection, historian Admin rights.
Certain Roles in RTIP have more restricted login to Historian Data source, Data Source for Hist is set for "Use these Credentials" -- set for a user who does NOT have access to those Restricted Historian tags.
When I log in as one of those users with the restricted role, i can still view the tags themselves, and also view data from those restricted tags in a trendchart.
Thanks for any advice.