❔ static fields for struct types

public static class StructA  
{
   public static readonly StructA  ValueA = new (..) ;
}

public static class Utility
{
   public static readonly StructA  ValueA = new (..) ;
}

public static class Utility
{
   private static readonly StructA  _valueA = new (..) ;
   public static StructA ValueA => _valueA;
}

public static class Utility
{
   // Initialize every time.
   public static StructA ValueA => new(..);
}