Hi Kurt,
Attached is a pic of two lifters.
The front one shows a light circular wear pattern which shows that it has been rotating as the cam turns. This helps distribute the pressure over a larger surface.
The back one shows a trough pattern through the center with raised edges. An indication that it is no longer rotating, & it's built in crown is gone. It also shows pitting in the center, the first signs of metal fatigue failure. The corresponding cam lobes showed similar pitting.
Cams are usually ground with a slight front to back taper on the lobes, the lobe centers are slightly offset from the lifter centers, AND the lifters are ground with a slight crown in their centers. ALL to promote lifter rotation which prolongs cam & lifter life.
If you actually have a couple of thousandths cam wear & the grinder did not make the lobes undersize, it's likely that the lobe's intended front to back taper has been removed.
The bottoms of the lifters should have a very shiney surface with a barely detectable circular pattern.
Your best first check is to remove the valve cover & observe the upper push rod ends for rotation with the engine at a fast idle. If they are all rotating, the intended geometry is still intact to some degree.
Sometimes on a new cam & lifters it's necessary to observe for this rotation & actually give the non rotating push rods a little help with your fingers during the first start. The lifters may be too tight in their bores, or the cam or lifters incorrectly ground. Hopefully they will take over the rotation on their own. If they don't, they are doomed to a short life. I've known fussy mechanics, myself included, to replace a new cam & or lifters to correct a non-rotation situation on start up.
I personally think that my use of the "new" formulation of Valvoline Racing Oil" with reduced ZDDP, the street legal variety, as opposed to the "Not Street Legal" formulation contributed to the beginning of my cam failure. I'm now using the same oil "VR1 Racing 20-50 street legal" along with 16 ounces of GM E.O.S. with each oil change. so far, in the first 1,200 miles on the new engine, the push rods are still rotating & the valve lash has not changed. I also think that some of the synthetic oils are too slippery for the cam to get rotating traction on the lifters & may prevent their rotation.
Since there are so many varying opinions on this issue, to each his own.
D