I would suggest the following:
- you start from a flat vertical wall split in triangles, roughly with the size you expect
- you move vertices horizontally or slightly horizontally to create the slopes.
- once it is done, you use JointPushPull to give the wall a unform thickness.
Bsed on this apporach, assuming this is suitable, a plugin would help to:
- show the slopes interactively
- impose a slope for a panel, by moving vertices, while making sure that the slope of other panels remain within defined bounds. This is a kind of optimization iterative process, with probably a convergence algorithm. This may be the difficult part, but even a simple algorithm would be more efficient than doing it manually.
- automate the JPP thickening
- Manage the export to CAD and document the wall (dimensions, area, slope, …)