Building a Collection of Subclasses and Modifying Their Public Members from the Inspector

I'm trying to figure out a way to have a component script that I can attach to an object in the scene that holds a collection of references to objects of type BaseClass but would allow me to view and edit the public members of subclasses of BaseClass in the same collection.

For example, I have a component script called CommandList that I attach to an object in the scene. It has a member public CommandHolder[]; where CommandHolder looks like this:

 [Serializable]
 public class CommandHolder
 {
     public BaseCommand command;
 }

Where BaseCommand is just some base class that we'll say has no public members.

Now in the Unity Inspector if we look at an object with a CommandList component we'll be able to define an array size for our array of CommandHolder elements. Then I can drag and drop scripts from my Assets into the public BaseCommand command field of the CommandHolder object in the inspector.

So this is where my question comes in. If I have a class called WaitCommand:

 public class WaitCommand : BaseCommand
 {
     public int seconds;
 }

And another called MoveCommand:

 public class MoveCommand : BaseCommand
 {
     public Vector3 direction;
     public float speed;
     public float duration;
 }

Then what I want is if I drag and drop a WaitCommand script into the command field of a CommandHolder element in my CommandHolder array then I want to be able to inspect the seconds public field in the inspector. I understand reason this doesn't happen is because CommandHolder expects a BaseCommand object so its only treating our WaitCommand as its base class and not exposing the public int seconds member that only exists in the subclass. So then how can I get the behavior I want?

I imagine this would involve some reflection, because I don't want the solution to involve a custom inspector class for each possible subclass of BaseCommand, I want it to just work.