Is anybody here using IB TWS for combo's (spread) on similar, but different underlying? Examples would be 2 leg Steepeners or Flateners on ZF,ZN, ZB? or ... COIL vs. WTI (or 2 * QM)? ... is it possible to construct a combo in TWS with legs on different futures contracts? (searching on ET found nothing) Thank you in advance for the help/advice.