Valve train geometry

"Narrowing the pattern may reduce the low roller side force on the stems due to lower roller-on-axle rotating speeds."
Narrowing the pattern by moving the shaft (and readjusting the checking pushrod) ust shows you are getting closer to optimum
way back in the day we locked the valve in place with a clothespin at half lift- that slipd so we graduated to a stem seal with a screw clamp
then set the cam at half lift and put the rockers and shafts on for a trial- moved the shafts around till we had the valve tip, center of the shaft, and the ball lined up with the ball as far up as we could get it- (and that three point line tangent to the valve stem )which was usually not far enough now we know there are easier ways...
what you will find as a result is less guide wear and rpm stability
lots of variables like longer valves and/or lash caps AFIK there is no easy way