Too many assumptions, real world/valve-trains ain't perfect, My 2 cents Have you ever over-reved (floated)a hydraulic engine, I've done it many times. Minimizing pre-load helps this.

CSK to be clear, you set you valves by putting them on the base circle, turning the adjuster until the lifter is fully collapsed, then back off a 1/2 turn? My next question is have you ever set you valves after the engine was run/primed? I would think that the one time, you could get to the bottom of travel was with a clean empty lifter. After priming any inconsistent residual oil would put them all over the place. Sometimes they won't move at all (or anytime in the near future). What then?

DVW funny you said that..... I was thinking you guys are overthinking this. O lash, 1/4 to 3/4 turn and move on.

I want to say good luck to the original post trying to get all the lifters completely bled down, to do the bottom of travel method If you go that route.