Serialize custom object as primitive in .NET

Question

In my code I have objects (and methods) that are working with quite a few IDs that are just simple Integers. To get a bit of help from the compiler when I'm setting values all over the place, I turned these simple ints into more strongly typed objects, kind of type aliases. Something like this:

public struct CustomId
{
    private readonly int id;
    public CustomId(int id) => this.id = id;

    public static implicit operator int(CustomId cid) => cid.id;
    public static implicit operator CustomId(int id) => new CustomId(id);
}

But as it's really just an int with a more specific name, I'd really like to serialize it just as an int so for example in JSON a Person would look like this:

{
    "Name": "ASD",
    "Id": 42 // this would be the serialized result of my CustomId
}

While I managed to build a custom JsonConverter for this case and it works fine if I'm using Newtonsoft JSON, I'm wondering if there is a better way of doing this, an attribute or an interface to implement (something from the System.Runtime.Serialization namespace), that most serializer frameworks will take into consideration, so I wouldn't have to write custom converters for JSON, XML, Protobuf, etc. serialization but could just rely on some generic solution.