Tom - I believe it was an adaptation that, yes.
The key to the hole at Lido was that in order to reach the green in two, you had to hit blind over a sandhill right in front of you, this at the inside corner of the dogleg, but worse, the rest of the shot was over the sandy wastes of Lido's off-fairway to a green that was at a most difficult angle and bunkered well (this can still be seen at W'hamp, if the alternate fairway, now gone, could be pictured as originally built) ..... sorry, if that sounds confusing - it was a complex hole I would love to build as was built at Lido
(whooops, there goes everyone to the drawing board ....... hurry guys, you can call it "your original" design :-) .... "hey this Raynor guy was pretty good after all"
Compounding the problem was that there was a huge waste area before the green that everyone had to contend with.
You said, "Tom Simpson did not enter the contest because his partner, Herbert Fowler, was a judge". ... he actually did submit but disqualified himself - they published it because the design was so good ....... I'm not sure "it was worth comparing with MacKenzie's" was what it was about Tom. It was just another really good hole - I think I have six of the entries around here in the files.
The second, third and another winner by a man named Walsham were pretty similar to the Rayor P-DL adaptation. I think Walsham's was the one that Raynor drew from ...... in the Walsham drawing with a compulsory carry short of the green was drawn as "Hills with Sand Pockets" which the judges criticized as a blind-shot problem - I think Seth moderated that to a flat waste area and used that for his version.
The judges, Darwin, Hutchson and Fowler, said there were 5 or 6 entries that were just about as good as the winner(s).
The Channel hole was far and away the best hole on a course with many great holes.
Incidently, for all you "diagonal risk/reward" fans of the Cape hole, the Cape at Lido was 378-yards - NO diagonal carry off the tee, and like the Cape at Fishers Island, the second shot carry was over hazard and the green which jutted out into the sandy wastland of Lido's off-fairway.