Mapping to multiple derived classes with Mapster

Question

I'm trying to map from one hierarchy to another. Both my parent classes are abstracts as I'd never need to instantiate them, only their children. I would like to use a single mapping config the constructor of each child rather than create mapping configs for every child individually but haven't been able to do it so far unless I put a default constructor in each child class. However, I'd rather not as I want my domain objects to be instantiated in a valid state. Does anyone know if this is possible with mapster?

Domain classes

public abstract class Parent
{
    public string Name{ get; set;}
}

public class A : Parent
{
    public string PropertyA { get; set;}

    public A(string propertyA)
    {
        PropertyA = propertyA;
    }
}

public class B : Parent
{
    public string PropertyB { get; set;}

    public B(string propertyB)
    {
        PropertyB = propertyB;
    }
}

View Models

public abstract class ParentVM
{
    public string Name { get; set;}
}

public class AVM : ParentVM
{
    public string PropertyA { get; set;}
}
public class BVM : ParentVM
{
    public string PropertyB { get; set;}
}

Mapping config

//Domain to VM mapper
config.NewConfig<Parent, ParentVM>
    .Include<A, AVM>
    .Include<B, BVM>
    ;

//VM to Domain mapper
config.NewConfig<ParentVM, Parent>
    .Include<AV<, A>
    .Include<BVM, B>
    .Fork(config => config.ForType<AVM, A>.ConstructUsing(src => new A(src.PropertyA)))
    .Fork(config => config.ForType<BVM, B>.ConstructUsing(src => new B(src.PropertyB)));

Unit Tests

[Fact]
private void DomainToVMMapper_ViewModelReturned()
{
    //Arrange
    string propertyA = "Test";
    var a = new A(propertyA) { Name = "Name" };

    //Act
    var aVM = _mapper.Map<Parent, ParentViewModel>(a);

    //Assert
    Assert.True(aVM is AVM); //this passes fine. I get a view model of A back
}

[Fact]
private void VMtoDomainMapper_VMReturned()
{
    //Arrange
    var aVM = new A() { Name = "Name", PropertyA = "Test" };

    //Act
    var a = _mapper<ParentVM, Parent>(aVM); //fails here - cannot instantiate type: A

    //Assert
    Assert.True(a is A)
}

Is there a way of passing multiple forked configs to the same mapper? Or am I going about this the wrong way? What I want to avoid is having to create a mapping config for each derived type & from/to combination and just throw a child object at a mapper based on the parent classes and the mapping knows what to do with it. And ideally by not using a default constructor. If I have to use a default constructor, what's the best way of making sure my domain model is in a valid state?

Thanks