First of all, I made a mistake.
When I suggested using Comp Cams Additive on the cams/lifter bottoms (because of it's tendency to remain where applied) , I actually meant Comp Cams Assembly Lube (part # 103).
Assembly Lube must be applied before the engine is closed. And apparently, you are all dropped in and ready to do the break-in procedure - so that ship has sailed. Forget about it.
I am not an expert by any means, so consider the source. But, as far as the supplemental zinc additive (whichever brand you choose):
For the break-in and the two subsequent oil changes, I have had excellent results with Rotella T 15W-40 and one bottle of high zinc additive.
After that I change over to Mobil 1 15W-50 (or 5W-50). This is just a personal choice and is based on my laziness/forgetfulness to change my oil on a frequent basis. Those two Mobil 1 products have a high ZDDP content (1300/1100). And, since they are synthetic, will retain their initial lubrication properties for much longer than conventional oils.
But, to answer your question; After the first two oil changes (with zinc additive), it is perfectly all right to just run straight Shell Rotella T 15W-40.