Include all navigation properties implementing interface type in Entity Framework's DbQuery

I have non-generic DbQuery and in order to optimize query I want to include all navigation properties with type implementing specific type. For the whole object graph, not only first level.

For a first level, I can propose my extension method:

public static DbQuery IncludeImplementors(this DbQuery dbq, Type typeToImplement)
{
    var includedPropNames = dbq.ElementType
        .GetProperties()
        .Where(pi => pi.IsNavigationProperty() && typeToImplement.IsAssignableFrom(pi.PropertyType))
        .Select(pi => pi.Name);

    return includedPropNames.Aggregate(dbq, (current, propName) => current.Include(propName));
}

I assume, that implementing extension method bool IsNavigationProperty(this PropertyInfo pi) is trivial

Is there any recursion masters?