I agree completely to the ease of getting broken and draining tank, very vulnerable. Ours, an '01 Elkhorn, was built with valve factory installed on back wall. Obviously OPs '02 Lance, another mentioned on his S&S, actually pretty common.
I finally was able to reroute line and relocate valve to inside of gen compartment, our of harms way but also dumps to ground instead of on top of bumper. But only because I cut hole in back wall to utilize and open up basement for another project-
(carry ladder) otherwise drain line inaccessible.