Hi, First of all thanks for your work !

It seems than the "Auto" constructor strategy struggle with this kind of readonly inheritence.

abstract readonly class Fruit
{
    public function __construct(
      public int $weight
   ) {}
}

final readonly class Banana extends Fruit {}

After deserialisation the "Banana" instance as not been correctly populated and a runtime error is raised :

Typed property Fruit::$weight must not be accessed before initialization

I managed to setup a test to demonstrate the behavior : https://github.com/aegypius/automapper-issue-284.