I have a couple of suggestions to clarify how the Highlight Location action works.
I was confused by the way that the Target and the Oval choices are centered on the mouse, but the rectangle is not. Until I spent a while exploring the topic, I thought this was a bug.
I have some suggestions for wording changes in the UI that may help clarify that difference and explain how this action can be used.
This is a petty personal preference, but when the title of the action is "Highlight..", please don't spell it "Hilite" in the UI. There's plenty of room to squeeze in those extra letters without resorting to Madison Avenue spelling.
When the display choice is Oval or Target, the action title says:
Highlight Target at MOUSEX(),MOUSEY(),100,50 Highlight Oval at MOUSEX(),MOUSEY(),100,50
Please add a little more description of the actual result, e.g.:
Create Target centered at MOUSEX(),MOUSEY(),100,50 Create Oval centered at MOUSEX(),MOUSEY(),100,50
I changed "Highlight" to "Create" because it seems more active and less passive to me and it saves a few characters of screen real estate to make up for adding "centered".
When the display choice is Rectangle, the title says:
Highlight Rectangle at MOUSEX(),MOUSEY(),100,50
Again, please add a little more description that clarifies the actual result. Because the original wording is exactly the same, I expected the behavior to be the same, i.e., the rectangle would be centered on the location. But it's not, the location is the corner of the rectangle. Here's my suggestion:
Create Rectangle with [ UL ] corner at MOUSEX(),MOUSEY(),100,50
There are other places within KBM where there is choice of which corner a position is measured from. A useful addition might be to enable choosing the anchored corner here as well. As a first left of fix, simply identifying the refernece point as the upper left corner would make it much clearer and show that this behavior is different from that of targets or ovals.
I hope this helps.