A:Answer Yes, you can modify your boot screen and ‘wallpaper’ as well. The boot screen image must be a BMP at 800x480 RGB 5, 6, 5 ratio placed on a usb with a text file. I found success using guidelines detailed on this web site: https://carboncarsystems.com.au/diy-change-kenwood-start-screen-image/
I used free software named ‘gimp’ to modify images to the correct size. The wallpaper seems to be any format and size, but the boot screen must be as above. Hope this helps.