I have the same configuration - Wally with Dish Tailgater package - except I use a tripod on the ground instead of the roof. I had an issue with the Dish that their technical support could not handle - they referred me to the Dish manufacturer (King as I recall). In my case the gear that rotates the Dish came out of it's track and I popped it into place. The Dish got tipped over just prior to that.
At what point, specifically, do you get stuck? Are there any error messages?
1. At the "Checking installation" step after Wally starts up?
2. At the "Scanning" step?
In the example above (gear out of it's track) I was stuck on #1. I've had other issues to troubleshoot at step 2.
I agree that DISH support takes a long time. I am glad to share we I've learned if you want.