I doubt any of us has talked with a Nissan engineer but with fifty plus years listening to engine builders from local racing classes to Indy I can assure you changing your oil at the first 1500 miles is good advice.....
You two are missing the point of this product. I can floor either of my cars on drive by wire and if it's not in gear the throttle blade barely moves. When I down shift I have to hit the pedal to the floor to rev match, even in casual driving. The throttle blade is not in sync unless it is in gear.
Sounds like you've never driven a manual transmission with a throttle by wire. I'm on my second (first a Maxda and now a Z) and I can tell you the throttle blade movement is not linear. When downshifting I usually have to floor it to get the revs even close in regular driving. I have not tried...