If the 22~23 meters width is an engineering constraint, then Spindrift2 is definetly the tool for the job.
Didn't realize that G3/IDECsport dimensions were really past .667 to .714. , old one was Nigel Irens 2007 design also used in Sodebo: width: 15.5(5) m , length central hull: 29.7 for IDEC, 32 for Sodebo.
15.5/29.7=.52
15.55/32=.486
Beeing the floats quite shorter, I'm not sure how to compare this, in 2007 IDEC's case:
15.5/24.5=.63
37/23=.62 for BPV / Spindrift2
I can't find the floats length for 2007 Sodebo, but the proportions are quite close, so BPV/Spindrift looks like a scaled up version of 2007 IDEC-Sodebo, while G3/IDECsport looks like an ORMA and has the floats about as long as the central hull.
Displacement is proportional to the cub of the size if it scales on the 3 directions, Spindrift mainly scales on longitud compared to G3, almost not in width, and no sure, for the hull, in height.
30% longer should be more or less 30% heavier if the other dimensions are not increased.
The hulls are roughly scaled, not the arms which have to be built to handle the increase of displacement, thus the stresses. That gives with the same coefficients of security something around 30 to 39 tons. I'ts a very rough estimation.
32 to 39 tons was the real displacement of the big maxis of the first era, like the catamaran Orange II, which is now the cruising boat, probably the fastest of the world, of Francois Bich, the heir of the Bic industry.
It's technically almost impossible for the moment to build a 4/3 maxi of 40 meters, unless a huge increase in weight, new hardware, new sail clothes and dozens of sailors to handle the monster. And there are cost constraints.
Besides with a length of 40m, there is no need to get the brutal and enormous stability moment of a 30 meters width, which implies the total rethinking of everything.
The small increase of weight of Spindrift originates simply as the hulls have similar cross sections as Idec Sport/Groupama 3 but are 30% longer. Just one dimension; a piece of hull in the center part of the hulls. After you tweak all that a bit, recalculate the arms, make a choice of stresses dissipation by a very slightly increased flexibility, which is interesting for keeping the angle attack of the foils of the submerged ama under sail stresses, a bit more carbon in the strategical points to keep the tall big rig on the deck, and the bows with the hulls. Et voilà, zis iz the rezipee to gett eazily espead. (heavy French accent, I can joke as I'm French and have a thick accent).
The first Idec (16.5 m wide) designed by Irens and Cabaret is a totally different tri of the tris designed by VLDP. The philosophy of Joyon, not a young man, was to get the "cheapest", simplest and easiest to sail maxi trimaran for a solitary. It's an ultralight only 12 metric tons for a 29.5 m length.
That shows the influence by the width of a tri on the weight. With a similar length, with a 16.5 width you get safely 12 tons, with 22.5 meters you need 18 tons.
The first Idec is a very "tender" and "soft" sailboat compared to Groupama 3 far more powerful. That is relative 99.8 % of the members of the forum, including myself, would need pampers while trying to sail alone Idec/Sodebo in a 10 knots soft zephyr on a mirror sea.
The 60 feet were totally bestial with big motorcycle accelerations and harsh reactions. I can say it first hand, as I have been "guest sit down here do not touch anything" on several 60 feet. The 40 feet were sweet baby girls compared to these wild 60 feet monsters, I had a rather good experience of sailing the F40s so I can compare the sensations. I can only imagine a AC72, that must be sometimes pure terror.
The length of the amas of BPV/Spindrift is 37 meters, 92.5 % of the length of the main hull. The first maxi Idec/Sodebo 24.5 m, only 84.5% of the 29.50 m of the main hull. 8% It's a huge difference. The ORMA tris were generally from 90 to 95%.