I owned a Rockwood 2604 Ultra Lite (different, I know,) and it had low point drains in about the same location. I had to stick my head underneath to see them. Mine had caps which I removed after blowing out the lines to let any remaining water drain out. I recently traded for a new TT the dealer had already winterized. They had removed the caps. I found them behind the outside shower door.
Roger, Sherrill, and Harley (Great Dane)
2016 Flagstaff V-Lite 30WRLIKS, Diamond pkg.
2012 F-150 XLT Screw 3.5L EB, 3.55
Air Lift AirCells, Blue Ox BX1500