Current version of IFrame doesn't handle Roles yet. However, you can download a module that is getting imported into core module and that we've created some time ago before coming on to the project team. it's call Viva IFrame and you can get it for free from Snowcovered.com

Most of its functionality will be added to the core module shortly.

IMPORTANT NOTICE: Viva Iframe is NOT in any way sponsored by anybody on DotNetNuke team. It is our side project that we feel would make sense to incorporate into core module.

Therefore, all the responsibility for it's functionality is solely with Viva Portals, L.L.C. and you should address all of your questions via continure.com.

Using IFrame module youj can pass jsut about any parameter found on User Parameters page (under Admin > User Accounts > User Parameters)

in addition, you can set up any custom parameters and pass-thru parameters. Also, you can include PortalId and moduleid.

However, there is no functionality to include Roles and RoleIds. It will. But if you need it urgently, feel free to follow my advice from above.

Also, IFrame doesn't support tokens (at least yet), so you would need to explicitly set those parameters in IFrame Options of the module.