"If that is a valid procedure for the OM60x motors, why does it not apply to the earlier OM616/7 which, I keep reading on this forum, require the use of a dial indicator?

Could it be that the dial indicator approach, which I understand allows for cam/follower wear, is obsolete, mistaking precision for accuracy?"--Thomaspin

Here is what I would describe as the reason to use the dial indicator method...

It specifies a Performance objective the engineers decided was important... it takes the movement of the intake valve a certain distance as something which should happen in a certain relationship to the rotation of the crankshaft.

All sorts of things wear in this equation... some may offset the wear in others, some aggravate them... this takes the bottom line and checks to see if the items are getting the primary jobs done at the right time.....