Yep! You got it all figured out. No one else could figure this problem out
but you. Congratulations.
You don't work for our President do you?

I'm not sure exactly what you are referring to, but historically engines
came with "break-in" oil. I don't know all the details, but I understand it
is low detergent oil that is intended to transport and precipitate the metal
particles from break-in better than normal oil is.

I'm seeing a lot of info (that I haven't quite digested) about modern
engines being designed and built differently in ways that either eliminate
or change the requirements for break-in. The honing process is supposed to
produce a more nearly ready cylinder wall, for example. I expect it varies
by mfr, too.

Mike

A brand-new engine has many new, roughly machined surfaces that need to
achieve their final finishes. As they wear in, much jagged metal is
released into the oil.

Break-in oil is very low in dispersants and detergents. The idea is that
the metal mentioned above will settle out of the oil and not risk
recirculating through the engine, causing damage.

Once the break-in period is over (but not before!), that oil is removed and
replaced with normal oil. It is not necessary (or even desirable) to keep
break-in oil in the engine past the initial oil change interval.

After the first oil change interval, the nature of the metal released into
the oil changes dramatically.