I launched the newly-tuned slim-jim antenna. With it hanging from the fan, it looked tuned. Hanging right next to the siding outside the window, it looked long.
I launched it into the tree to hang right below the quarter-wave. Hanging in the tree, it looks well-tuned. I compared both antennas simultaneously with the 2 Quanshengs, and the lower slim jim measures 10-20dBm lower than the higher quarter-wave when receiving.