I think if your comparing the latest Cube Orange Plus to the 6X Pro it’s really a Honda vs Toyota kind of fight. They are both capable units and it will really come down to what features do you need/want that will seperate the two. Either will fly your drone just fine.
H8 vs X8 is just a firmware configuration. No difference in the hardware choice for that regarding the controller. The cube or 6X would be fine and have the same layout for outputs.
The main difference between these, and the reason for the big price difference, is the IMU in the 6X pro. That IMU chip alone cost ~$375 (qnt 1 pricing).
Any supported flight controller with 8 outputs will do that. Not really sure what you are getting at.
FRAME_CLASS,3
FRAME_TYPE, 3
And move on. A $65 board will do it.