Gary, I went through this same thing in 2008 when we bought our trailer. I was told by the dealer I purchased it from that they could install a receiver hitch on the back of the frame for our double bike rack that wouldkeep the Lippert frame warranty but the cost with the hitch and having it certified welded to the frame was $700. To say the least that was not worth it to us. I then called Lippert andasked about me installing a receiver hitch by drilling 4 holes in the frame to bolt it on and was told very quickly if I did it would void the frame warranty.
Now things may have changed over the last couple of years but only Lippert could tell you that. If you are buying your trailer through RVW why not ask them if they can install the hitch without voiding the frame warranty. If they say yes get iton paper that they have confirmed with Lippert and it will not void your warranty. Hope this helps.
17 Chevy 3500 DRW 4X4
16 Mobile Suites 36RSSB4
2 Mini Dachshunds