The first few minutes of operation on a new cam is the critical time when extra lubrication and/or ZDDP is necessary. The wear pattern between the cam and lifters is being established during that time, and the absolute worst thing that can happen is to allow the engine to idle. Lots of oil is being thrown off the crankshaft and connecting rods at higher speed, so the cam and lifters are being flooded with oil splash. I've seen race cams get worn out in the first few minutes of operation when the break-in procedure was not followed.
I like to get the engine in as good a state of tune as possible - - - -valve adjustment, ignition timing, coolant level, etc. as close to correct as possible so the engine fires up with a minimum of drama. As soon as I see good oil pressure, I bring the RPM up to around 2,000 and hold it there for 20 minutes or so. Monitor the coolant temperature closely- - - -it's not uncommon for trapped air in the cylinder head to cause an overheat condition during the initial run-in, so avoid that possibility at all costs. After 20-30 minutes of fast idle, the engine can be slowed down and final adjustment tweaks can be done if desired. That's also a pretty good time to do a hot retorque on the cylinder head, final valve adjustment check, etc.
Jerry
