Under power, there's a fair chance it will be wings level during level flight without tip weight. Overhead maneuvers will be more pronounced with up/down tip.
For me, it's an aid for level wing landing. The tank is empty, the ship is floaty the last few feet before touch down and elevator control is less effective. When that happens, you might break a wood prop.
All of my current fleet of vintage combat ships have wing tip boxes. On my 120MPH "Scrambler" design, it's quite an effective trim tool.
Just my.02