Remember, the break-in is an estimate. If I were you, I'd turn the gas down. If you're throwing brass 20 feet or more and destroyed a buffer, the rifle is telling you it's overgassed.
The break in is to prevent malfunctions from happening when you start off as parts wear against each other a bit. Some rifles need it, some don't. Some might have an issue that break in won't resolve.
In my completely non-expert opinion, switch to setting two and see how it shoots. If its still slinging brass quite a distance, go to one. If rounds are only going a few feet, bump back up to three. If its just right, you got your sweet spot.