As Boeing couldn’t produce a better result; I would say perhaps;
Leave A/P engaged until hearing the “Airspeed Low” warning. Thus maintaining G/S. Then reduce the flaps.
This worked.
Deliberately going to airspeed low warning to improve gliding distance? I'd be surprised if Boeing would produce any recommendation in that direction...
From my understanding of the report this was only a consequence of the fact that the AP remained connected (on the contrary of what the PF wanted), thus being an inadvertent and non deliberate situation. If your PF was distracted enough not to realize the AP was engaged then I'm not sure that his primary goal was to bring such an heavy aircraft down to stall speed while still over 150 ft.
I don't agree with you when you say that since there couldn't be better results, there is no need to discuss about it. I anyway congratulate you for your action on the flaps which made the difference that day. Nothing to say about your PNF role but there's still something in the report which remains unclear and certainly not satisfactory:
The report is very confusing when saying the PF intended to disconnect the AP at 600 ft, then that he believed it was disconnected and finally that he omitted to do it because of some distraction until the stick shaker activates below 200 ft. I'm very curious to understand what could be distracting the PF, preventing him to control the aircraft for several hundred feet during an emergency situation, which is basically his primary and unique task.
If the PF didn't realize that the AP was engaged while he thought it wasn't, it means the aircraft wasn't under control, which I don't consider satisfactory and I'm quite puzzled that nothing is being said about that.
Could you please take some time to clarify what is the meaning of "omission" in the report? Were you aware that the AP was engaged? Were you aware that your PF thought it wasn't? That's why cockpit communication is important, thus interest in the CVR transcription.