Last night I trying to draw some stuff on a BTCUSD chart using an iPad I was going a little nuts. I was trying to line up a pitchfork over BTCUSD across a wide range and felt I was battling both the tool and auto-scaling at the same time. I couldn't reposition the bottom point of the pitchfork after the initial drag because it was too far outside of the auto-scaled range. See my public idea chart titled "UP?" from 7/20 and note the bottom point of the pitchfork is off the autoscaled screen.
After the initial placement of the bottom point, manipulating it by dragging was impossible due to chart auto scaling. Relocating it manually was also difficult because it took a long time to keep the angle of the trend line I was trying to achieve. If there were a way to automatically maintain the angle of the trend line while adjusting the X or Y of the 2nd and 3rd points of the pitch fork (auto-adjust the Y when X is adjusted, or vice versa) it would have been easier to draw what I was trying to accomplish.