I’ve tried Modern version with my A/P settings.
I made a FPL for this purpose with 2x 90° left and 2x 90° right, with 10nm between each turn. I flew it at 6000ft at 150Knts IAS.
The result is not as precise as the 208 I used for reference, but not so bad. It need some time to recenter on the line, but never goes far and corrections are smooth. It don’t fly through the line several times or fly along with an offset as seen last time.
It’s behavior seems to be the one of an old technology A/P system and servos with a modern intarface.
For an old timer it could be considered as more realistic than if it fly “straight on the line”.