There is still planes with issues, however it gets a little better but there is still work to do.
I bet they threw in there numbers from the books, no real world pilot with good flight experience tested these planes. The once I flew / Flying are not what i would say “Realistically made” to include : DA62, Baron, A320, The Cessna 172/152 are close enough, just the mixture can be improved.
Again… I don’t know how they decided or measured the performance, but even if they went by the book, the performance are based on Max takeoff weight and standard atmosphere in most cases.