Copied from team thread as I feel there's continuity and relevance here, not yet visible although speculative it does seem like something is coming to this car that may need keen eye to view for coming races.
With such extensive change it would seem there's fundamental issue that can't be "adjusted" out of to bring performance.
The good thing, if successful, is that recognition is there, with an outlook able to match and solve that.
Some things that lead my view on this:- they gave views of suspension spring stiffness which really are "bread & butter" itens in race team production abilities. They can easily make what they want at any rate they need. There's been discussion of softer springs and different bellcrank curve for CL and appear to hold the advantage over LH in absolute pace, which to me suggests that there exists a basic core structural integrity / level problem within tub & gearbox stressed structures.
If the spring rates are simply ramped up in attempt to concisely control travel (height and hitting the track as evidence) then to ultimately fail, suggest the spring "grouping" is stiffer than the structure supporting it. Tbat gets them into a setting "loop" that looks to invert any gain they are attempting to achieve.
There has been rumour about gearbox integrity from the start and coming from Bahrain. The "box" itself is normally a unit containing the gear and diff etc as one piece, this "housed" in an outer casing exoskeleton unit (the part we see in build images) to take all if chassis load. This also ultimately structured to facilitate wing mount and rear crash structure architecture. If that component has to be changed, then crash test etc would logically be part of the development to sign off. Its not a short timescale for this being a more fundamental part of chassis layed down early in development.
This would highly likely feed into next year, at least in effectiveness terms. If no way of getting around it now, they've got to jump into it anyway.
If they have either undershot the torsional performance through design OR in build, there's no real answer but to change this.
You can get, multi rated suspension in rising rate, non linear, progressive, regressive, all three type within one suspension stroke at different points of movement, end stroke support "platform" damping shift, along with geometry shift ..... just in a DH bicycle rear suspension system. Just an illustration of what is possible in fairly mundane and relatively inexpensive system in general market. These F1 engineer team have far, far more information and support to enact their systems into chassis. If they can't do that, it seems to confirm some level of basic structure compromise exists in preventing that undoubted knowledge being used to correct this car.
Something fundamental in there is wrong.
Ordinarily, to run lower a stiffer spring rate would be used, set then to lower static height (the situation they acknowledge doesn't work) but keep needing to "jack" it in preventing ground strike demonstrating loss of control, or more correctly the opposite outcome from their changes. Torsional performance of chassis in lacking, classical in this type of response, never resolving, failing to "play" to book as logical adjustment is made.
It's not without that in history though, the previous SF seemed likely in the same area, with exclusion also caused by plank wear at COTA and when running competitive pace. Also characteristic in all of these lineage from 2022 being notably fickle since 2022. The TD 039 APPEARED to take away a floor flexing "loophole" that would have masked this aspect.
Monaco wouldn't necessarily punished this if true

not all races the plank would have been checked either.
Something in the core design is lacking, finding it now MUST take precedent for everything this team wants to achieve.