Stock setups don't usually bounce around the level that much. My guess is that this has to do with the TPC setup. The car was built with a certain range for the oil level, and I expect that's no longer valid or appropriate for the TPC changes.
Still, FWIW, the stock setup on a 987.2 says it's about 0.42qt per bar... so if you put in 2 quarts, that certainly seems like WAY too much. Again, not knowing what TPC did, we are just guessing... but if you did that to a stocker, then you're likely well into overfill and are risking damage to the AOS (new or old).
It sounds to me like this is not something you have the desire or ability to work on, which is fine. But it's going to be an expensive proposition. Like others said, if you really want to keep it, I'd pull the TPC stuff off, as it's a big risk without having the support you need. Alternatively, if you can find a shop willing to tackle it with this stuff, then have at it. I imagine most won't want to do this... and if they do, it's going to be expensive simply because it's going to take a good deal of time to figure out what's going on, without proper support from TPC.
I'm coming into this blind - does TPC even exist anymore? Can you contact them for help at all? From what I have read "between the lines" they aren't around?