Internal insulation - Multipor or double-shell wall construction

Again a question that won't let me rest. We are currently renovating a farmstead and are not coming to any conclusion regarding the internal insulation.

The current wall structure consists of two rows of old kiln-fired bricks. Don't stone me, but according to our architect's documents it is 30 cm, but I actually think it is less, 24 cm. I can measure tomorrow if necessary, but I don't think it influences the question.

Recommendation of the architects regarding the internal insulation:
Architect A: kiln-fired brick -> lime plaster -> 20 cm Multipor -> lime plaster
Architect B: kiln-fired brick -> lime plaster -> 6 cm air layer -> insulation (e.g. mineral wool) -> Ytong or sand-lime brick, both wythes anchored -> lime plaster

The latter variant would be attractive to us insofar as we could improve the statics at the same time and compensate for the slant of one wall (10 cm over 225 cm height). However, I now read in almost every forum only arguments against variant B and for variant A.

What is actually the difference to new, double-skin masonry? It is executed exactly the same way, only that it consists of a clinker and is of course not executed in the thickness of 24 cm. According to calculation on ubakus the dew point is between the walls in both variants. In the case of Multipor, it absorbs the water and slowly releases it again when it becomes drier or is ventilated accordingly. How does this work with variant B? The air layer would have to be ventilated, or where should the condensate go?

This topic is making me a bit down. Especially because there are two architects who have actually renovated many old buildings and recommend two different approaches. ...can't they just agree :p

20 cm Multipor

Really 20 cm? That easily becomes passive house standard and you’re poor for it - three digits per sqm.

Now, however, I read almost only arguments against variant B and for variant A in almost every forum.

I see variant 2 more often (although not monthly) in the commercial sector when the listed facade is to be preserved. Then simply a "new" masonry with insulation on the inside is built. As a layman, I wouldn’t know offhand why variant B shouldn’t be used if the space allows for the thicker wall construction.

Correction - it's only 10 cm ;)
Thanks for the inquiry at this point, I actually assumed 20 cm and only asked architect A again upon your question, who has accompanied us with questions so far and also developed the rough renovation concept.
Variant 2 is now apparently out for us after all (unfortunately), since the wall would have to stand on our already finished, new floor slab, which according to the architect is not designed to carry walls/loads of that extent.

However, both architects agreed that we should leave the slanted exterior wall as it is. It belongs to the house and structurally the slant apparently has no negative consequences, as long as we eliminate the supposed source of error. This source of error is a cut middle purlin. The previous owner apparently shortened it at the time in favor of the attic expansion. We will support it again and additionally insert another purlin between the middle purlin and the foot purlin. With this, I hope the problem is solved.

Also, instead of the floor-to-ceiling windows, we will only slightly extend the historic window openings (approx. 25 cm). Then the slant will no longer be as visually noticeable (4 cm) and sufficient light will come in that area anyway through the 3.00 x 3.00 barn door, which will be fully glazed. The masons/carpenters should agree on the door.

I hope this is a good decision in the long term.