Any time you can cut weight off the inside of an engine, it's going to be better for it. Lighter pistons and rods are easier on the crankshaft, block, and bearings. Lighter valvetrain requires less spring pressure for a given rpm.
This is essentially a max-effort engine build, but we have rules to follow.
We have to use stamped steel factory rocker arms. They can break and the rocker pivot balls can burn up. To counteract this, we have the rockers cryogenically treated and REM polished. We have tins that redirect any
oil splash back to the rocker arm. We also try to run a minimum spring pressure....enough to keep from losing control of the valvetrain, but not enough to break factory rocker arms.
When the valves are light, springs are light, retainers are light, etc., then you effectively need less spring pressure.
The intake valve weighs 68g. Exhaust valve weighs 63. Titanium beehive retainer is feather-weight. It all adds up.
We simply can't turn 9000-10000 rpm with this setup and do it reliably. If there were no rules, then I'd be using T&D or Jesel shaft rocker arms, steel camshaft with DLC coated tool steel lifters, etc.