When I was looking at docks, Triumph stated that the only thing that will not void your warranty is to build the bunks to the specs they have for the trailer. Period. This was prior to the bankruptcy, re-org.
Bottom line, none of the drive on docks would be acceptable to Triumph. Give us an update if you end up getting one. I may still consider it, once my lift gives out in a few years, since they are not honoring old model warrantees anyway.