1. Can you detect when the SIP is going to pop up ?
    if you can,the you can get the screenshot just
    before the SIP pop up.
    Then draw the semi transparent Keyboard on top of
    the screenshot (just use only obscured part to make
    it faster to draw)
    FYI,I use this trick on Win98 & it works
    Years ago,Linux also use this trick,but now it
    already fully support transparency (not pseudo
    transparency)
2. You can just hide the botom panel only when the SIP pop up,then
    unhide it when the SIP hidden.
    I notice that everytime we use SIP to type something
    we almost never use any other part of the bottom
    panel.
4.What I mean is just like KLMN mean + more enhancements
Actually I'm a programmer too,but I've never create things on WM.
I don't know about WM API,but if it is just like WinAPI then
there will be another way instead of using WM_PRINT alone.
If you can make it semi transparent,it will help many user (they may donate more as well....including me)
FYI I've tried the 0.16 Alpha (I can't find any 0.15) & it is very buggy,so I replace it with the old 0.14 which I like better.