Jon – Yes, post any score using ESC regardless of tournament or not.
David B – The point is all handicaps we “assign” for the tournament are from rounds you (should) post. We’ve never placed someone at a handicap index that isn’t based on your own scores. No information is disregarded and many players will play based on their current index. In reference to that one time you played to a WA index (5.7) instead of your submitted index (10.4) the difference may have been less drastic if you posted your tournament scores to your own index.
Edit: failure to post tournament scores from the WA the previous year is grounds for immediate ineligibility.