Lemmee see if I got this right;
You demand accuracy, but tell the newbe it's ok to put the plunger of the dial indicator into the pushrod cup.IDK. That's a bad idea. Even the bottom of the lifter is NOT flat.
They make a proper tool for that job and it's pretty cheap.
If the heads are on, the job just got harder
I'm a newbe at degreeing too, having done it less than a dozen times. But I figured out real quick that the pushrod cup was not the thing to use. So I had a tool machined for me. Now they make the tool.