Not too sure if this helps, but I've seen break-in for a lot of aviation engines. I worked at a shop that overhauls Allison V-1710 engines (1710 cubic inch V-12).
After a complete overhaul, we start them up and run them at idle for about as long as it takes to get to normal operating temperatures, perhaps going up very slowly to maybe 1000 rpm or so. Then we clean the screens (change the filter). Then we run them 10 minutes or so, first at idle and then at 1000 working slowly to 1500 rpm. Then we clean the screens. At no time do we increase rpm quickly. always slowly. Then, for the next 4 - 6 hours, we run near idle until warm and slowly work up to 1500 - 2500 rpm, run awhile, and slowly work back down and then back up again.
What we're looking for is for the valves and rings to seat. When the exhaust outlet has a light gray coating that isn't wet, the rings are seated. After than, run it like you want to run it. Of course, we are running straight pipes without a muffler in WWII aircraft. I'm not exactly sure how the exhaust on a muffled engine would look, but I follow that general procedures for 4-stroke engines for about 8 - 10 hours, just to be sure. Most times, it takes 4 - 8 hours for a WWII Allison V-12.
The instructions for the diesel SHOULD give you an idea of how long it takes to seat the valves and rings. As stated above, don't run it at one speed for extended periods during break-in. After break-in, it really doesn't matter.
Once the rings seat, oil usage should drop way off. If it doesn't, then the rings never seated.
Just as an aside, when I was racing cars, I separated the ignition from the starter. If you run a high horsepower engine, it's best to get oil pressure before starting. So it always sounded like my engine was hard to start, but that wasn't the case at all. I ran the starter until I saw oil pressure on the gauge and then closed the ignition, assuming it had been longer than about 20 minutes since I ran it last. My engines always looked brand new when we disassembled them later.
If I had a tractor, and I will, I'd do the same thing. Separate the ignition and starter, assuming you have an oil pressure gauge. If you don't, add one or not as you see fit. Might pay real dividends in cold climates. Most engine wear happens during startup without a good oil film on the parts, and cold makes it worse. I never rev a cold engine above idle, but that's just me. I wait for some temp before going above idle. Everyone has an opinion about that one, and many think otherwise.
Fortunately, I don't pay for their engines. I know a few people who do whatever they want to cold engines and never have a problem. I also know the other side of it. Those guys spend a LOT more on engine issues than I do. If you're racing, you MAY be spending someone else's money. If you are talking about your own tractor, you're probably spending your money.
Spend it wisely.