Valve Clearance on Larger Camshaft and Flat Top Pistons

My post is a direct quote from his book. If you believe that information to be incorrect I'm curious, what part you disagree with?

When you say " checking this stuff" I'm guessing we are still talking about checking undeflected and deflected lift measured as outlined in his book and that we haven't moved on to another subject?
pushrod deflection IS a big deal with dragracers hunting every last bit of horse power and needing longivity...