I would not be wanting to add extra ZDDP to an oil even if the additive was free. Maybe on a new rebuild, But I would not be using an expensive oil for the first couple of hundred miles.
Yes, totally agree for normal running using proper quality oil for our engines but this is for running in a newly built one. I was trying the find the right balance between oil that was suitable to allow rings to bed in without glazing, while having enough ZDDP in there (via an additive) to try and protect the cam and followers.
I was planning on using something like Comma Motorway 20/50 (dirt cheap I know, but that's not the point) and a ZDDP additive in the right proportion.
However, looking at the link in John SB's post re Lucas Oils, their break-in 20/50 seems to be ideal, so I'll use that for the first 200 miles.