I fully agree that Alfred Nichols was present and active on the starboard side during preparing, loading and lowering of the aft lifeboats. This might have even started when Lifeboat #9 was uncovered early, but as Symons twice confirmed that he saw and worked with Nichols (during the loading and launching of Lifeboats #3 and #1), IMO it is more likely that the earliest Nichols could have arrived near Lifeboat #9 was just after 01:00 am. But that clashes with his supposed encounter with Lightoller, which was presumably during the loading of Lifeboat #6; so unless Lightoller was making up the entire thing about the gangway doors (IMO he would have no reason whatsoever to do so, as I have said below), it would have been more like 01:10am by the time Nichols came to Lifeboat #9. If Wilde had countermanded Lightoller's gangway door order and instructed Nichols to help with the aft starboard boats instead (like you suggested), it would tie-in nicely with that timeline for Boatswain Nichols.
During the inquiries Barrett said nothing about seeing the boatswain by #13
True, but that alone cannot be used to 'confirm' that Nichols was not there. That line of questioning quoted by you above was by Senator Smith on 25th May 1912 on board the
Olympic,
after Barrett had already testified at the British Inquiry and
after that
Ulster Echo article was already published.
The fact remains that Barrett got into Lifeboat #13 and it was most likely from the A-deck.
Someone must have been in charge there at the time; Barrett testified at the British Inquiry that there was no officer there and later told Senator Smith the same thing in the above session quoted by you. It must have been true because Barrett would have known that there was too much risk of another survivor from Lifeboat #13 ( or even #15) refuting his claim
if an officer had been in charge after all. Furthermore, by the time Senator Smith interviewed him, Barrett would have known for certain that there were no veiled accusations aimed at his own survival and so hiding something would not have been in his own interests. The person in charge when he got into the lifeboat would not have been important to him in any way and so he would have had no reason to make-up Nichols' presence.
Barrett testified at the British Inquiry that when he arrived at Lifeboat #13 on A-deck, he could hear an officer issuing orders above on the boat deck. IMO, such a statement is way too committing for even a moderately intelligent man to make-up and completely unnecessary. So, why would Barrett have volunteered such information that was irrelevant to his own survival and something that ran the risk of being refuted if untrue? Moreover, it tallies with Moody getting ready to lower Lifeboat #15 to the A-deck and Murdoch having crossed over to the port side. And as I said, since Barrett's whereabouts in the 5 minutes or so before he reached Lifeboat #13 were of no particular interest to anyone, he could very easily have told everyone that he arrived on the boat deck first and was ordered by the officer there (Moody) to go and join Lifeboat #13 on A-deck; no one would have been able to disprove that and Barrett would have known it.
Related indirectly to all this, I believe that Murdoch did supervise at least the latter half of the loading of Lifeboat #10, not an easy task against the port list and the ensuing gap (stories about the near faller etc). Therefore, if Lifeboat #10 was lowered at 01:50am (which I believe that it was), Murdoch must have arrived there about 10 minutes earlier.
So, it brings us back to
who really was in charge of Lifeboat #13 on A-deck when Barrett arrived and got in. I don't believe it was either Murdoch or Moody for the reasons mentioned above. It might have been McElroy, but if so Barrett could just easily have told the Inquiry that the Chief Purser was in charge and ordered him in. It would not have made a difference to Barrett - either personally or officially - between Nichols and McElroy; therefore, the fact that he told
Ulster Echo that it was Nichols specifically at least merits consideration if not blind acceptance.
Also, if as even you feel Sam, Nichols was working with the crew on the starboard side aft lifeboats soon after 01:00am, the 'natural progression' would take him to Lifeboat #13 at some later stage. Since #11, #13 and #15 were loaded from both the boat and A-decks and with some overlapping, they would have required sufficient supervisory senior crew; IMO, they had them in the shape of Murdoch, Moody, McElroy and Nichols. After Lifeboat #11 was lowered to the sea and Lifeboat #13 to the A-deck, things had progressed sufficiently for Murdoch to leave the other 3 in charge and go across to the port side to sort out Lifeboat #10.
The big flaw in the W-F-B lifeboat timeline IMO is the 25 minute gap between the launching of #7 and the launching of #9. They were forced to create that huge time gap because of the unsupported testimony by Scarrott of McGough lowering #14.
Did you mean launching of Lifeboat #1? In the WFB Timeline, Lifeboats #7, #5, #3 and #1 were launched at around 12:40am, 12:48am, 12:55am and 01:05am. According to Symons very clear testimony (where he both identified and named the boatswain), Nichols was present for the launching of #3 and #1, the latter at 01:05am; from that point on, IMO here was a gap of 20 to 22 minutes before Lifeboat #9 was launched, but a few things happened in between. The senior officers met briefly for the firearms meeting; although this may have lasted only 3 minutes like Lightoller said, IMO it started only after
he arrived. That would have been after he launched Lifeboat #6 at 01:10am (still going by the WFB sequence, which I know you now don't accept but it is out of scope here to delve too deeply into
that) and so they would have come back out only by around 01:15am. Then there was the disturbance with Lifeboat #2 with some crew members having got in opportunistically and although Murdoch was not directly involved with that, there have been comments about him being briefly seen on the port side around that time. Murdoch very likely went to where Lifeboat #9 was partially loaded but by the time loading was completed and it was lowered, it is more than likely that it was between 01:25 and 01:28am.....just like the WTB timeline suggests

.
Therefore Sam,
as things stand I will have to disagree with your opinion that Bill Wormstedt, Tad Fitch and George Behe were "forced to create" any gap in their lifeboat launching timeline. But I am willing to wait for the jury to return with their verdict.
Is it not the case that probably Lightoller created the myth of the E deck door being attempted to be opened as a 'smoke screen' for the lifeboats not being fully loaded?
That's theoretically possible, except
why would Lightoller have done so? Until the Second Officer himself testified about his encounter with Boatswain Nichols and the "order" about the gangway doors, no one had even associated the latter's death with Lightoller. Nor did anyone know about that order; certainly no one in Lifeboats #8 or #6 saw any open gangway door. So, unless there was a modicum of truth in it, why would Lightoller have shot himself in both feet by admitting that he gave Nichols an order that even he was not sure was safe or practical (see 13909 & 13913)? It was only Lightoller's testimony that led a lot of people to accept for decades that Boatswain Nichols took about 6 men below-decks to carry out a highly questionable order and all of them died trying to follow it.
If Lightoller wanted to cover-up the fact that the first few lifeboats were only partly loaded, there were simpler excuses. On the port side, he was third in the pecking order after Captain Smith and Chief Officer Wilde, and the latter was around during the launching of Lifeboats #8, #6, #12 and Collapsible D. Lightoller could easily have said that the Captain or Wilde ordered him to lower Lifeboat #6 when he did and no one could have found out any different. AFAIK, the only lifeboat that Lightoller was completely in charge on his own with no one senior to him nearby was Lifeboat #4 and that was reasonably fully loaded anyway.