Hello, very nice addon you have created here, been looking for simple but configurable unit frames for a while. :)
I have however found an annoying bug. It seems that when I target someone who doesn't have a target but whatever I had targeted before him had one, the target of target frame doesn't get hidden but shows the old target of target.
Should be easily recreated by targeting someone with a target (e.g yourself), and then target someone without a target (e.g a NPC).
I have one feature request also, would be nice to be able to set most of the options through a slash command, sometimes it's very hard to get the frames position and scale at the correct value with the mouse. :P