Thanks to all for your responses and good ideas. For the moment, I think I'm going to tap the booster into the 12v DC circuit to one of the reading lights in the bedroom, and put it on the shelf above the bed. That places it right inside the front wall of the camper, which is fiberglass rather than aluminum. Since I keep the TT connected to shore power almost all the time, I'm also thinking about a small switch or simple connector so it's not on 24/7/365.
Any reason not to use that power source?