Follow up on this thread now that the solution has been found. It looks like the part below from Amazon was in fact defective and after replacing the original bad MAF, I never had a good one to begin with.
This part generated two error codes. P00BC and P0174. I am reporting it to Amazon as I don't think this part works, like ever for a 2007 E90 with N51.
However, the part does generate ok data in the Torque app as well as Carly app. It reported Kg/hr numbers that were fairly normal (10-25).
I ended up getting a used, BMW OEM German made MAF from Ebay with a 1 year warranty. After clearing codes and doing 5 drive cycles, it has passed emissions and idles smoothly.
https://www.amazon.com/dp/B077W5G7S5...ing=UTF8&psc=1