No, I did not use auto-trim to 'assist the flare'.
If you read carefully, I am saying that you can not fly the aircraft B737-400) deliberately out of trim above 500 ft AGL and it is also not good practice to do so due to distractions like checklists, etc. I also did not run the trimmer during the flare, as it will strain the auto-trimmer machanism.
You need click-click the trimmer just before you start reducing the thrust, pushing slightly forward (not to change your touchdown point) and relieving the forward pressure as you close the throttles. Relieving the fwd pressure actually makes the aircraft flare itself. Looking at the end of the runway, you will have a natural tendency to pull just hard enough to touch the main wheels first.
Yes, the checkies were happy with it as long as I was aware of the stronger nose-up pitch on the go-around. So, it is better to go click-click once you are asured of the landing.