I have a lot of numbers on Shimano & Campagnolo shifter pull lengths, many done with Alex Wetmore's tool. They are not as precise as you might like but they can get you started. I did not have the late Campagnolo 11 speed. My Campy 12 speed is internally routed and I built it before I had the Alex Wetmore tool, so all I have is the overall pull at 31-33mm which is not very accurate. It is not easy to measure the pull at the rear derailleur. I do have the Sensah 12 speed*. If there is interest I can convert from the .xls spreadsheet.

My understanding is that Campagnolo Athena 11 rear is the same cable pull as 2014 & earlier Chorus/Record/SuperRecord, with the caveat that it does not allow more than one cable release shift at a time. Can this be confirmed?
My understanding is that Campagnolo Potenza 11 rear is the same cable pull as 2015 & later Chorus/RecordSuperRecord, with the caveat that it does not allow more than one cable release shift at a time. Can this be confirmed? Also the comment is that the Potenza rear derailleur has a weaker spring so may not shift as well with the Chorus/Record/SuperRecord (may need really slick cables and housing for example)
Can anyone comment on the cable pull for Centaur 11? There is some belief that it is not the same as the other two.

As with 70sSanO, I have a lot of non-standard configurations. Most of my bikes do not have standard rear sprocket sets. All my derailleur bikes have shimano freehubs. More than half have Campagnolo shifters. I have had good success with soda can shims and thinner spacers than standard in cases where required. I also retime the sprockets as needed, and dremel cutouts as needed.

My experience is that knowing the numbers will allow you to make a start with the setup. But there will almost always be final tuning needed with sprocket spacing or something.

My experience with front brifters has been - build it and try it. For example, if you need more or less movement change the front derailleur cable clamping and see what happens. But I have Shimano RSX front derailleurs with Shimano 9 speed brifters and a half-step+granny triple**. I have Shimano Tiagra triple shifter with 105 triple derailleur shifting 24-24-47 on a Stronglight 93, and yes I know you cannot put a 34 on a Stronglight 93. But I can. I use custom "buttons" and 4mm bolts, and while I have broken 6 or so bottom bracket spindles, including a Specialized FACT, I have never broken any of my many 4mm chainring bolt setups. This also requires dremel on the derailleur because the "modern" Shimano triple needs the shift ramps and the Stronglight 93 chainrings do not have those. I have Campagnolo 11 speed chorus/record pre-2015 shifting an $8 front derailleur 24-42-52 on Shimano cranks, on a bike with Campagnolo 11 speed rear, I have Campagnolo 11 speed front brifter with a Shimano 105 10 speed front derailleur and 26-46 TA 5 pin cranks, 11 Campagnolo rear with modified SRAM Red 10 speed derailleur. I have SRAM Red front brifter shifting a Dura Ace 10 speed front modified on the bike with the Campagnolo 12 speed rear. I have di2 with 26-46 chainrings on the Specialized FACT with Lightning 94bcd spider. I have Shimano RSX triple left brifters shifting Sturmey Archer S5 hubs (where the 2 speed side is a Campagnolo 10 speed brifter operating through a TravelAgent). Similarly an RSX brifter and travel agent on a bike that can accept any of the Sturmey Archer ASC, TF or S3X. I have Campagnolo Veloce Escape triple brifters on a bike where the inner shifter position is fixed, and the outer two positions shift the front derailleur between the 2 chainrings for freewheel - yes it has 2 chains and switches between fixed and derailleur with the front brifter. For the inspiration search for bichain fixed free. I have a Campagnolo "10 speed" front brifter shifting 10 rear sprockets with an 11 speed chain and a Shimano 9 or 10 speed 105 rear derailleur, and unequal sprocket spacing, on a bike where the left side has a trials freewheel backdriving the crank to simulate a multispeed fixed; I believe 2 shifter clicks are needed for the innermost shift. The setup right now has a downhill top forward gear, and a higher than that backdrive gear, and even the trials freewheel is not sufficient to keep the backdrive lash low enough for my liking. It was relatively OK but not great when both were around 74 inches with a Suntour rear derailleur and an Atom/Regina 5 speed freewheel.

The Campagnolo 12 speed front brifter did not seem useful, so it is sitting in the box unused.

*I thought the Sensah 12 speed would solve my winter mitten shifting, but the motion of the shifter is not as nice as either Shimano or Campagnolo. There is a LOT of lever movement for the next larger rear sprocket. The shift joy is not there, so the single tooth spacing shifts do not happen as fast as desired to make the bike as fun as the mainstream. And resting the hand on the front brake lever, something I do when the hands are really cold, causes the front to shift to the small ring, which is not desirable. And it is very hard to set it up so that when on the large rear sprocket and you attempt to shift to a larger rear sprocket the bike does not shift to the next smallest rear sprocket. I had thought this last was not possible, but the last time I rode the bike that at least seemed OK.

**Half-step is not worth it. First, half your shifts will be both front and rear. Second, you will not remember which shift you did last, so you will not know how to make your next upshift or downshift without looking, and at night you cannot look. Third, the front shifts are all the tension part of the chain which is not as good as rear shifting where the untensioned chain is moving; this is important when you are upshifting at speed, but even more important when doing the double shift downshift under power for the slight grade change. Fourth, is that there are no ramps available for the front shift, and that will be non-trivial to create on your own.