Your remarks target the actual issue, my only benchmark is the TomCat F18 HT project.
The curved crossbeam has been engineered by Mr Guillaume Verdier who is actually in charge of Safran a racing monohull.
For the F18 HT they have not used prepeg just basic epoxy in mould abd they achieved 10 kg and it is stiff enough to avoid a dolfin-striker.
As far as I know the prototype seems very stiff. The crossbeams are plugged into conical housing on the hull's deck, a bit like for centerboard.
The max height of the hull is 46 centimeters, because crossbeam section at the deck level generate very little drag.
Their boat seems to be very stiff, but it is also a consequence of the hull's stifness.
Of course set up process will be 15 minutes longer, but the only alternative is to make the bet that your carbon platform is not at risk when you are working 600 km from your sailing club. For a Hobie 14 no brainer, but for a 20 000 + € toy, I prefer to be organized accordingly, and the cost is to unfold completly the boat for storage, I will have the same issue with a A-Cat, so 3.10M width is OK;
I think your project makes sense, the only issue is a "legal" one: If you want the same leverage and righting moment, your overall width would have to be highter than 3.10, unless you fold the leeward wing to meet max width class rules, otherwise you give up righting moment.
The next step is to find a cheap tool/ construction process in order to use prepeg&autoclave for the first crossbeams.

Cheers

EK