The reason for such a short pre-load of say 010 is in case the hyd lifters pump up at high rpm. If the preload was, say, 080, that would mean the valve can theoretically increase max lift by 0.120" with 1.5 rockers.....& the valve could hit the piston.
If you have adequate valve spring tension, you will not get get lifter pump up. Internal lifter travel is typically at least 0.150" & you set the pre load anywhere within that range. If not sure of the available preload, compress a lifter in the vise [ slowly if it has oil in it ].