I'm not sure I understand what part of my post you don't agree with. I said that if the GP's were recently replaced, leave them alone. If they are old, they should be replaced while the head is off, because otherwise they WILL FAIL eventually and the labor will be 5x as much after the head gasket job is done. An extra $75 in parts on a $3k job as preventive maintenance. Are you saying someone should leave old (or unknown age) GP's in just because?
msyoder's case is different, he just replaced the GP's and doesn't need to while the head is off. My one 300D had them done just before I bought it. My other one will get 6 new ones (IF I pull the head or intake manifold) because I have no records of them being done in the last 8 years and 100kmi.
BTW- do you currently, or have you ever, owned an MB with an OM603 engine? Or worked on one? I can't imagine you saying this would be a waste of time or money if you have...