FluentValidation syntax for conditional validation of collection elements

ConditionalCollectionValidation.cs

public class TestValidator : AbstractValidator<Customer> {
  public TestValidator() {
    RuleFor(cust => cust.Orders)
      .SetCollectionValidator(new OrderValidator())
      .IncludeWhere(order => order.Amount > 50);
      
      //OR
      
    RuleFor(cust => cust.Orders)
      .SetCollectionValidator(new OrderValidator(), includeWhere: order => order.Amount > 50);
      
  }
}

What about:

RuleFor(cust => cust.Orders).Where(order => order.Amount > 50).Apply<OrderValidator>().End();

or

RuleFor(cust => cust.Orders).Where(order => order.Amount > 50).Apply(new OrderValidator(someArgs)).End();

where the End() call functions like jQuery to escape up out of a nested set of rules.

Alternately, the Apply() could escape up the same way.