Well, many will tell you 18 ways to skin a deere ..... yes E at the end.......
but since it is new, I would run it not WOT ( I would stay below max rpm) for a while.
I am one that advocates running the machine WHERE THE MANUFACTURER designed it ......... thus the 540 pto on your Tach.
Some if not many have this "feeling" that running it a hair above idle saves the engine stress and will make the engine last longer........... Running the engine at the designed torque and HP curves make sense from a engineering stand point but many know so much more than those engineers that designed the engine in the first place
As for fuel usage - most of these machines actually can use a little less diesel at 2k than at 1k - not enough to matter, but there is always the argument to save fuel.
You will find that the machine will cut BETTER at and around the PTO label - on your machine I believe it is closer to 3,400 rpms.