Running close to coil bind is to crush harmonics out of the spring cycle, and often just a necessity of room under the retainer . The goal, changes where, and what you set up. Spring longevity, and performance, are two different goals. High HP na goal engines run really high intake pressures, and very low exhaust pressure as one example. I've seen longevity goal run a 2.3 set up spring where 2.1 would have worked at near coil bind. The cam never challenges the spring, Not enough action to start a harmonic, and they go 200 passes on what would be 50 at 2.1. They do pay for it in needing high quality valve gear.