I broke in a GM Pontiac Ram Air 4 hydraulic flat tappet camshaft with 1970 GM Pontiac Ram Air III dual valve springs. Those springs had 125 lb. seat pressure and 325 lb. open pressure with 1.5:1 rocker arms. I set the lifter preload while the engine was still on the engine stand. After the engine was installed, it started immediately and I took it to 2500 RPM and held it there for 10 minutes. The cam survived the break-in period.
That was about 10 years ago using Crane Cams Moly-Paste #99002-1 on the cam lobes and distributor gear with Valvoline 10W-30 All Season motor oil. The motor oil did not have any more ZDDP 10 years ago than it does today.