Value vs reference types when using interfaces in C#

I would like to create a type in C# with value like semantics. It is immutable and it has a low memory footprint. However, it is mostly going to be accessed via an interface it implements. In this case, a value type would have to be boxed which means that the actual value would have to be copied from the stack to the heap. Therefore I wonder if there is any advantage at all in using a value type (struct) instead of a reference type (class)?

To illustrate my situation, I provide the following example of an interface I with implementations ReferenceTypeImplementation and ValueTypeImplementation:

interface I
{
    int GetSomeInt();
}

class ReferenceTypeImplementation : I
{
    public readonly int i;

    public ReferenceTypeImplementation (int i)
    {
        this.i = i;
    }

    public int GetSomeInt()
    {
        return i*2;
    }
}

struct ValueTypeImplementation : I
{
    public readonly int i;

    public ValueTypeImplementation (int i)
    {
        this.i = i;
    }

    public int GetSomeInt()
    {
        return i*2;
    }
}

I would almost exclusively use these type using the interface I like

I i1 = new ReferenceTypeImplementation(1);
I i2 = new ValueTypeImplementation(1);

Is there any advantage in using ValueTypeImplementation over ReferenceTypeImplementation?