The module on the right is trimmed because the first module is an inch too big. The workaround is to use centre alignment with Trim Last (Extend last removes the final mullion on each end, erroneously.) But it shouldn’t be working as it does with start alignment.
Currently the cell size is calculated from the interior face of the frame, without taking into consideration its width. We thought that was a good idea, but it’s true that can have some limitations. We are thinking about adding an option to include the size of the mullion between each cell.
What do you think about that?
This is an example of the two options that you would get:
Still there is a wrong approach
Whit axial dimensions, the far left and right panels have different sizes. It would be best to keep both possibilities, but for extreme posts (or mullions) there should be another value option. And it applies not only for VA curtains, the same problem is with railings.
The first of your examples, Ramon, provides a consistent module.
The second alternative doesn’t. This is the same method present before the window muntin issues was corrected. It simply seems like an error to me, I don’t see any use for it.
The best way to create this is probably to research and understand the way Curtain Walls are actually specified in the construction world, how they may differ when they are used as infill glazing panels (where a “frame” MAY be a useful part) as opposed to the entire skin of a building (no frame), and how they differ from Storefront Glazing, which is more properly thought of as Windows (with frames). And to study how AutoCAD Architecture, and Archicad, provide Curtain Walls (for one thing, a differently dimensioned “frame”, isn’t by default a part of the assembly, as I recall.) The measurement from centre to centre of the mullions is more useful to me as a designer, especially in a true curtain wall (where it’s the entire building skin, which doesn’t have a ‘frame’.)