Guy I ride with got a new 16 Cat 600 this year with the e-pump. He didn't have to add oil to that either. We took it on a trip and it used quite a bit at first and then not as much after that. Same deal you are describing.
I like that automatic adjustability, in fact I expect it in a 2017 injected model.
I haven't put injector oil directly into the tank since I had a 600 carb in 2009.
Bear