Here's a link to Lippert's site and info on the Goosebox... https://lci1.com/goose-box. This is the only gooseneck adapter that Lippert endorses so it wouldn't void your frame warranty. I know that there was a post from a while ago from GD Customer Service confirming that but a search on that link ends up in "page not found".
Thanks. I did call Grand Design to verify and am waiting on a return call. I was suprised that Silverback told me that it wasn't approved. I thought they used Lippert frames too
JD Adams from GD responded that the Goosebox is approved for those that are interested. This is one more reason that I am leaning towards the Reflection over a Silverback or Columbus