I think you fella are trying to fit all Biarritz holes into some sort of single model.
In general:
Macdonald sees of hears about this hole dramatic hole on the Biarritz course, the Chasm.
He needs a long (200-plus yards) one-shot hole to go along with what he is trying to accomplish on par-3s - testing various clubs by building various lengths par-3 to fit four sections of the golf bag;
1. A short hole of from 135-145 (don’t nit-pick the numbers, they are approximations from the 19-teens and 1920's based on scorecards from his earlier courses)
2. An Eden style hole - middle iron test, from about 160 to 175 (160 was the norm)
3. Redan, a long iron or wood-club -the average Redan length on his earlier courses were, on average, 187 yds.
4. missing a long hole ........ my thinking is that he wanted one unreachable on the fly. Here is where a lot of us get into trouble. We keeping thinking about this stuff in the context of today’s play. Think about those players not hitting the ball 200-yards on the fly but counting on a ball that will bound 50 - 60 (and more) yards. There were hardly any holes in the British Isles that fit this mode for him besides the hole in France (I knew they would be of some help at some time).
Big Charlie builds NGLA with only three par-3's leaving out the long par-3. My personal opinion? He felt he didn‘t have the topography for a Biarritz hole on the Southampton property.
So he builds the first Biarritz hole, ground level at Piping Rock - hard turf, a running shot.
Next at Sleepy Hollow he builds a goofy down hill short Biarritz of about 200 yards that is so bad you cannot even see the swale and the “front” fairway area just a flat landing area. That hole is part of the “lower course” - the 7th.
Over time he and Raynor build Biarritz holes on their courses that fit a general model - again, single green fronted by a swale (if possible) with a landing area (fairway preceding the swale. No so-called “double green” (in those days).
I think his side, strip bunkering (when used) was to simulate the left and right greenside hazard problems on the France green ....... probably close to the cliff-line on the right. I have no idea what was on the left of the French hole.
But to me the key is that, yes, there was a basic model but they were not anchored to it and often used the local terrain and the wishes of the membership as a guide for what they were going to build.
1. Westhampton CC: a reversed horseshoe around the fronting fairway - a one of a kind.
2. As earlier stated, often there was no swale but just a push-up green, usually on “moderately hard” courses, like Blind Brook, and courses where the membership did not wanted a killer course. “Charlie, we can always go out to National if we want to get knocked out but for every day place give us some moderation” (a Blind Brook paraphrase).
3. Essex County a downhill Biarritz cocked at more than a 15-degree angle to the line of play with no bunkering on the right but on the left there was bunkering for nearly 100-yards up the hill.
4. A few, very boring, ground level holes with hardly a swale.
Occasionally they hit the jackpot - Yale, Fishers Island and such.
They were not forcing this early Biarritz model into a course unless it looked right - if it did not, they modified the hole. Some Biarritz holes were cut into a hill; Tamarack. Many were dramatically built up on level land; The Knoll, Chicago etc.; out on an island, Creek
One of the neat things about CP-16, to me, is the angle the land sits on, relative to the line of play to the green. Apparently, a 200-yards carry straight on but less of a carry the further to the left you opt to play. Nice - an optional-play par-3.
So, the question seems to be, did Seth Raynor “see” what became the 16th hole as a definitive Biarritz hole? Who the heck knows! But it was certainly part of his overall routing of the course