This is actually what brought me to the single line suspension. Lets me eliminate the tree's distance as a variable. Then the only problem is the further apart they get the more the line sags as a result when loaded. means you have to put the line pretty high on the trees when they get really far apart.
Perhaps in the mad scramble for sexy light weightness I and everyone else has forgotten the most important function of gear – not that it must weight nothing, look good and be cheap, but that it must keep you alive and increases your survivability.