Well, you didn't doubt, you jumped directly to a bunch of undocumented conclusions based on something we do not even use! Your PlaneMaker understanding also appears low. Your conclusion was it is "flyable" but needed your "corrections". Sorry to jump on you like that but we take our engine and flight model very - VERY - seriously and we have now spent 8 years (!) refining it, still are, and are very proud of it. (Also I said "possibly", unlike you I did not conclude it was the best...)
The hardest part of making an accurate engine thrust model is getting the detailed information you need on the specific engine in question - and understand what you read! It took me 15 years to finally get this. (Austin after 25 years in the business still has not got this good information...) . Detailed engine data is highly proprietary information that you will not find laying around on the internet or in books. You need engineering manuals, engine maintenance data, FDR data, empiric data etc If you want a really accurate thrust model you need detailed information on all altitudes, temperatures, mach, N1 etc. And we do...
So feel free to question the flight/engine model, but we expect any claims/conclusions to be well documented and not just an "opinion". Off course in new XP versions things get broken, so if something "changes" from what it used to be we would off course like to know about it.