Of course. When they're doing the work free, they get to do it however they want. If they drill into the head, they have to pay to replace it.
When its out of warranty, due diligence is prudent.
Consider the cost comparison. Youll likely be replacing those manifold screws every 65,000 miles. For me, that means about 3 time during the time i own the truck, since i tend to buy them used and drive them till theyre junk.
$600 per stud replacement job at the dealer x 3 replacement jobs = $1800
So, i can budget up to $1800 for the tools to do the job and the training/time to learn it.
Then, i get to use the tools and training for other ****
Like building my Smoker...
$6000 of steel plate, tube, axles and tires. 100 hrs of labor and another 40ish hours CAD drafting, solid modeling about a hundred parts.