Brett....I tell ya....you are making me remember a lot of stuff!!
Let me mention a couple of things....
I used a 'right sized' wood dowel to insert into the cam bearings and then pulled back and forth to see if there was much slop in the bearing.
As the balls wear down the 'in and out' clearance would increase.
Comparing with a new set of bearings would help.
The next thing is the wear in the spiral cut on the cam. You can use a tool and move the point of it back and forth across the wear mark to see how much it is worn.
Same thing on the shaft.
Still another place I had trouble with is the face of the cam that contacts the lifter.
The ramp on the lifter was pitted and wearing away causing some problems. The actual lifter was ok though.
You might try increasing the oil content to perhaps 15% total or perhaps 1% castor to help out with wear for a total of 16%.
Also...I used 1oz of acetone to help with the idle.