Yes, there is a flaw: by moving the bb shell inboard towards the seatpost as you suggest, there would be a greater and perhaps impossible restriction on chainstay design/diameter/etc.; not a minor consideration.
I'm not moving the BB shell, all I'm saying is that there's unused space on the outer side that can be used to expand the diameter of the shell at the extremes.
There's nothing I can see that would be getting in the way nor would it by any means upset the geometry of the frame, interfere with the chainline or allignment of any existing crank for that matter.
Essentially it would not be that different from Shimano's system, the difference is that they've wasted an opportunity by sticking to all existing standards for 100% backwards compatibility.
IOW, and I may be wrong, I've as yet not seen a "standard" frame that sports a downtube as wide as the BB shell.
The widest ones were invariably hydroformed alu frames.
Although carbon would allow to do the exact same downtube design, there's just no point in it.
So you end up with unused space at the end of the shell, space I'd like to see used to make stiffer BB bearing assys.
Whether that is a good idea remains to be seen but so far I can't see anything that would throw the idea straight out of the window.
Sorry if my shabby explanations are the cause of confusion, a simple drawing would clarify it much quicker no doubt.
Finally, to repeat: this is where these stiffness issues get ridiculous: if component A) is stiff enough that there is no discernable flex and negative effect on performance who gives a d#%n if component B) is 1%, 10%, or 10,000% stiffer, really? Campa/Phil/etc. bb's are still going strong, absolutely fine for most purposes, after how many years now?
I feel the crux of the exercise is to make lighter BBs without compromising stiffness.
I agree with you entirely that there's no point in making a stiffer BB than strictly necessary.
However there is a point in making things lighter at equal stiffness.
After all the less Watts wasted the better the results of the racer are likely to be all else kept equal, no?
If you lose even a few miliwatts of power in a BB per revolution imagine the amount of energy wasted over a six hour race....
Stiffer BBs simply make for more efficient transmission of power.
Remember, anything that can move loses energy...
The only movement we want from our bike is one forward
By going Ti the Deda DPower combo for instance drops from DA10 level of stiffness to Centaur grade. Another big drop is from Record (30% stiffer) to FSA Ultimax Ti or TA Axix Ti.
Sorry to say so but that's just cheap engineering on the part of the parties involved.
We all know it's not the Ti spindle's fault even though the material is of course less stiff as we all know.
Just that they took a design optimized for a steel spindle and swapped that one for a Ti one....
Because the market wants a lighter BB, or so they think.
IMHO the market wants a lighter BB that just as stiff as the heavier one, that's all.....
In the meantime it pays to know what you're wasting money on and what's worth buying.
To me at least that's what true ww'ing should be all about.....