Completely Removing Logout Button

I am having an issue configuring BIG-IP to completely remove the logout button.

We have the 'Home Tab' disabled for our portal in our F5.

We have a portal configured that points to, as an example mydomain.com.

When I login via the F5 it correctly displays content from mydomain.com and the BIG-IP logout button does not display on any of our web applications, as we want.

However we have one application that we are using URL Rewrite for IIS on mydomain to rewrite a request to another site, mynewdomain.com.

When I try and access that application we have a logout button that displays in the top left of the screen. How can I remove that button? My understanding was that if we disabled the 'Home Tab' for the portal that the button would not display.