dont forget image editor,let say if you are using four different cameras so that you can edit them to make them look the same if not there is no raizon to but it. Also audio mixer strong wifi range. at 5 HDMI should be enough,more USBC.
you need to work on the switcher to be better,like when you switch to look professional,its too many HDMI in it.I hope that people can trade yolobox pro ,extra for the extreme.