One should be somewhat careful with generic and sweeping statements such as "High altitude stalls, the simulator just does not work" as some OEMs have supplied the required data. Certainly brands A & B haven't yet and their current datapacks are (probably) more than lacking.
The TDMs can only simulate what they are supplied with and no one within the TDM world would ever suggest that they attempt to make a simulator anything like the real world (because that is neither feasible nor remotely possible without sustained G cues), only that is matches the approved (and typically OEM) supplied data