If you look in the About dialog it says about caching not being performed while the window is open. The same loop that runs the tray icon does the caching. Likewise while the About dialog is up, nothing else is going on. I think it's likely that a convoluted way of trying to monitor 2 window loops would be more likely to mess up.
Part of it is due to the fact that AutoIt is an interpreted language. As an example, I have an ActiveX Control to does MsgBox with unusual background colors. Optionally it has a Help button. When you press the Help button in Delphi, or VC++ or C# or VB 6 it fires off the help context event. I can display some help info while the MsgBox is still open. I've tried it in AutoIt and Python and it fires the Help event after the MsgBox closes. Not very helpful... just one of the limitations of running code that's not truly compiled. Of course there are advantages too, like Hotkeys that are easy to change on the fly.
That's also the reason there's no minimize button on the window frame. Sort of giving the hint that the window is not meant to be left open all the time. Just pop up and launch, and disappear.
I'm hoping eventually I'll figure out how to have adjustable background color to the window and still have Glass work the way it does with black. Depends how complicated. I have a feeling I'd have to paint the glass area with solid black etc.. pita