Set up two layouts--one optimized for FileMaker Clients and one optimized for IWP.
Conditional formats do not work with IWP clients and thus your ability to hide objects on a layout are extremely limited.
The following script step can detect that the user is an IWP user:
If [ PatternCount ( Get ( ApplicationVersion ) ; "Web" ) ]
Thank you Phil
I have made a layout with a dialog stating that the feature is not supported via web login.