I agree with you but we already went through this when I added positional-only arguments and everyone complained that Cython and other projects were broken and we changed a stable API function so I am just mentioning that we are here again.

Honestly, I think what you describe makes sense and this constructor should never be stable (as the Python one is not stable). If we add column offsets that's another parameter more than we would need to add. But in any case that's just my opinion and we should reach some conclusion collectively, that's why I mentioned this here.