Unfortunately, I don't have much experience with HDMI splitters, so you may want to continue looking into this with others.
If you can't get it to work, you may already know the G74 also has an analog VGA port (which you may be hoping to avoid using?) that you can use instead with the HDMI port if necessary?
Don't have a whole lot of experience with USB to external monitor connections either, but that may be another option you want to look into and if it make sense even use it as part of a docking station?
Sorry I don't know more about them, but just wanted to mention more ideas that you may or may not want to look into.