Display an arc from your last suitable before etops, using your one engine out dist. As this is based on zero wind crossing the arc puts you into etops (EEP). Continue this in fix page 1 and 2 with all your en-route alternates as they come up and when you cross the arc again you are non-etops (EXP) . ETP can be entered either in flightplan or in fix pg 2, thus using only pg1 for arcs.
AUH