This surprises me. I could swear it was you who said additives don't mix and I believe it. The oil will just be what it is. 10w30 0r the additive. That's what the engine sees .
I never said they don't mix. That's just not true. I have said I prefer to use a premixed oil with ZDDP already in it, but it's getting so expensive, I have to find other means now.