That will be a nice step up from a 1020 to a new 4520, last year I went from the 820 to a 4520.
About the diverter valve, I have one on my 110 with triple front and rear circuits and also have a skidplate to protect these hydraulic lines. When it is all hooked up it would be a good idea to see how much of this stuff is vulnerable to damage from the underside of the tractor.