Beyond ~6k on synthetics while the oil holds up the filters tend to clog and bypass. If you changed your filter at 5k and added a quart or so to top off you would avoid that issue.
On the break in, while the engine may be run at the factory for the initial break in, the fact is as it get's some mileage and things polish in it will improve as friction increases. The initial break in usually lets the rings seal but as the piston walls get polished with more mileage friction will be reduced. Same for most other parts in the engine.
