My take on it is that running low/OEM type pressures is extra insurance for break in. The tool steel lifters themselves help as well. But personally I have always swapped springs with anything over 300lbs open when I ran conventional lifters. I've been running the Schubeck/Smith lifters for many years now without issues. (Knock on wood!
).
With all the variables, it's difficult to but a "safe" minimum/maximum number on the pressures for break in. Opinions may vary too. Play it safe.