Edit: d'oh - I misread, the addendum is doing exactly this...

I don't understand the need for the macro-fu to generate the case values. The use of switch_step++ in each previous case seems to drive that, but couldn't the same be accomplished by setting switch_step to a constant?

  static int switch_step = 0;
  switch(switch_step) { // Falls through between cases
    default:

    #if METHOD_0_AVAILABLE
      switch_step = 0;
    case 0:
      if (method_0_works(...))
        break;
    #endif METHOD_0_AVAILABLE

    #if METHOD_1_AVAILABLE
      switch_step = 1;
    case 1:
    ...
  }