Attitude can play a large part in some responses, my last post in this thread I deleted, as the response I got back wasn't one I expected when trying to help. Of all the people on this forum, I am going to say I am the most qualified to pull off a conversion like this. I will explain at the end of my post.
This is what I would like the OP to do;
Go to your nearest Kawasaki dealer, find out the part number for the ECU of the 2017, compare that to the 2016 to see if they are the same, if they are great.
Also get a price and delivery on a 2017 Instrumentation display, see what is involved in the ordering process, what I mean by that is a serial number of your bike required to order this, the reason I ask this is due to liability, if it is possible to cause damage to your engine, they will refuse to sell it to you. Again I will explain this possible damage and the reason for the ECU part number.
If Kawasaki is smart, they would have used the technology they developed in the gear indicator to improve performance of the 2017, presently we have a closed loop oxygen sensor, crankshaft position sensor , vacuum, air temperature, speed sensor. What if we input what gear you are in in relation to the TPS to determine what you as a rider are asking the ECU to do in response to what it is able to do. The information is already there as to engine RPM and speed , however they may make use of the computer/whatever you want to call it when displaying mileage / fuel consumption .
Many of the signals are either pulse or analogue , the TPS is analogue, inserting a blocking diode would throw the signal off by 0.7 VDC , just a example, this would involve scaling the raw signal with the blocked signal, so that both devices sharing the signal saw Identical readings.
Not saying that will be the case, just a example I have had to deal with over the last 40 years. Kawasaki does not share the design of the electronics of the ECU or of the display, when the magic smoke escapes it is gone forever.
So the big problem is if they share the information of crankshaft position etc with the display and have produced a different ECU and or changed the wiring to prevent signal feedback to accommodate these changes, I think the outcome of hooking up the 2017 display if it caused damage to the ECU of the 2016,that you would have more to say than oh well, it's just money.
One last thing, owners manuals and service manuals are not readily available, Kawasaki has decided to charge for both, although the owners manual is downloadable for free if you put in your Zip number, or register with your bike info.
Like my last post, if this isn't what you are looking for I can delete it too.