Break-in? No, this kit has been around since 2005 or 2006 and had many miles on it. Not a break-in issue.
Tuning? Maybe. But again, it's run for a long time before being put on ice in 2007 until 2020.
Timing? Unlikely, for the same reasons, as well as the fact that I never messed with the timing, and it runs like a champ in general.
Since my engine was smoking copiously due to burning oil leaked out onto the cylinder, and since there was a clear oil trail between the cooling fins on the underside, I'm going to stick with my original diagnosis of air leak around the base gasket. Thanks though.