A lot of the reason they now you synthetic oil from the factory is because the manufacturing procedures and tolerances got much better. They finished the cylinder walls and the ring materials are better so they no longer need conventional oil for things too polish together for a bit to seal properly.A lot of that thinking about synthetic oil would not allow proper break-in was false. Just the engine manufacturers not committing to the new oils even though a lot of synthetic oils start with the same refined base as the conventional oil they are replacing. Use of conventional oils for the first 50 hours to aid break-in has been removed from the owners manuals. And changing the break-in oil at 5 hours has been eliminated on engines with oil filters,because the break-in debris gets filtered. So the interval is now to go by the first recommended oil change interval so 50-100 hours. Almost all vehicles come from the factory with synthetic oil in the engine. Auto engines don't even have a break-in oil change, and basically never did. My 2011 Ram 1500 uses synthetic oil in everything but the engine. And the reason it doesn't use synthetic in the engine is because the synthetics in the 5w20 oils don't meet the Chrysler oil specs,
The Kohler synthetic oil change kit sourced from Amsoil and has a 300 hour change interval, which in most cases may be excessive. The old 25 357 06-S conventional oil now has been replaced with 25 357 64-S full synthetic. So Kohler doesn't even offer a conventional oil even outside of the synthetic oil service kit that they are pushing sourced from Amsoil.
They can build engines so well today that they don't even need a break-in period at all.
That was not the case 25 years ago and it's still not really the case in outdoor power equipment because these engines are low performance little turds.
They don't get nearly as high quality or expensive machines that bore and finish those blocks as an automotive engine does.
They also don't get nearly the expensive or high quality rings etc.