Question measuring duration @ .050

the number of cards I've seen that have timing event for at valve are few. When you add mechanical items, varying rocker ratios, bad tappet angles you only confuse/muddy the measurement

Almost every one for an ohv, pushrod, rocker arm style are at the tappet.

Go look at any sb, bb, hyd, solid or roller cam card from manufacturers and I'd doubt you'll find a card at the valve. It's not the norm, nor std practice.