I would love to be able to set the scale of the symbol key in the same fashion as the plot view. ie. 1:25, 1:50 etc.. Currently using custom symbol sets the symbol key to a smaller scale than the view or views in the plot and it cannot be manipulated to match your scaled plan.
For those having the same problem as I am the work around I'm currently using is to create my own symbol key by dragging the symbols onto the plan and adding plot annotation. The draw back is the annotations have a box around them and a line back to the symbol and it doesn't calculate the fixture counts for you.