Brief message to Deema at UK forum.

Sorry I wasn't able to answer your question about balancing keyboards.
Briefly, it depends on what type of action.
Mechanical action organs you can balance the weight of touch to some degree by doubling the soundboard pallets in the bass to reduce the positive pressure applied to them but it's a tricky balance best avoided by using lower pressure wind. If you increase the leverage in the bass you increase the key dip to a point where it becomes rather stodgy.
Electro pneumatic avoids that problem by using electrically activated exhaust valves.
The keyboard has become a series of electric switches. 
The other benefit of electro pneumatic is that you are free to use higher wind pressure and get more volume.
You can also borrow pipes from different ranks. There's a lot more to it than that but for what it's worth I hope it gives you some answer.
Sorry to have been evicted. I enjoyed our interaction. 
🍻.