I think you may have posted in the wrong community area so may not get any replies. I would move your thread but I don't have access to. Could you please repost? I think the community that you need is:
There isn't an option to only launch the portal when a policy is waiting.
However, you could set the delivery method to be a required policy and have it show UI so the user can see when a policy is trying to run.
Or use launchpad to publish the software in the startmenu from the users... Frank - Axle-IT