Hdmi out

I just recently purchased a Raspberry Pi 7" Touchscreen to connect to my Raspberry Pi3 model B.
I have Kodi running on it and it works fine. I want to be able to use the HDMI out plug however when I plug a HDMI cord into it nothing happens. Is there a way to have both the touchscreen and monitor via HDMI out running at the same time? I have used the config file trick display_default_LCD=0 but this disables the LCD. Is there a way to have them both?

Until someone does the scary low-level work to make it happen (modifications to the videocore firmware if I’m not mistaken), it’s simply not possible.