@koshy
You should be able to determine which frame buffer is active by using chdkptp: if the overlay is correct, it's the first buffer. This method is obviously for ports that do not report the current bitmap buffer. In your latest g7 samples, "inside canon menu" has the 1st buffer active, the rest is 2nd (address is @ 0x6ae8).
I don't need more memdumps at the moment.
It didn't become clear if you have the A410 to compare. So... A410 works fine, screencap attached.
I have that cam, I was the one who added the support routines, so I assumed I tested it back then