I'd have opted for an LS4 as well.
When bad, our seals don't typically exhibit the smoke on cold start behavior. Not sure what it is about them, they don't seem to. I've seen quite a few folks do the seals during an install and find that they use much less oil between changes. It's common enough.
On the LIM gasket, take a closer look at it. There is no oil going through it. The only place that oil can possibly travel is up a bolt that goes into the cooling jacket or the oil return of the head. For oil to get into the combustion chamber it would need to wick up a bolt (no pressure) then come off the threads where the LIM meets the head, get through the gasket at that point and through the seal of the gasket at the intake runner. While remotely possible, it's a tough sell.
