Smooth sail vault modeling

[lcorsiniJFCG2]

I was asked to model a cross vault using an infill element between the vault intrados and the architectural floor. Possibly without using generic models, except for the adaptive metric generic model, but if it were possible to model it as a slab, the adaptive model would be useless because only the "roof on surface" family can be applied.

I modeled as shown in the attached images. From bottom to top, the model consisted of: adaptive metric model; roof on surface; infill walls associated with the vault and the slab above; and slab.

According to their instructions, the architectural floor must be cut from the vault surface so that, once the section stratigraphy has been assigned, it is visible. But I haven't figured out how exactly.

Are there solutions that meet the requirements? Or are there alternative solutions?