[Schwarzeritter]

No, that's not pragmatic or accurate.
1. It is true to some extent that very large cylinder bore diameters do have a slight or extra amount of blow by then that of say a smaller cylinder bore. And this is true to some extent
on boost applications. But not 1liter at 700-1000miles.

2. It's un acceptable, you really need to discuss this again with management.
If the manager is un-willing or not capable of creating a solution, then you need
to contact Porsche NA or Contact Porsche AG if you are not getting satisfactory results.

3. For the love of god, do also make sure that they infact are filling the engine with enough oil, you'd be suprised at the thinking of some, they get worried or hyper cautious and sometimes the tech is in a rush, being pissed on by superiors, lazy, etc and they are short half a quart or sometimes a quart short. Also what kind of climate do you live in, you may require a different viscosity. However, Porsche needs to make it right.

Good Luck-