KXW now handles puzzles in SSX mode - that is, on arbitrary Kakuro grids. I have retained the restricted domain requirement, so all words must have property CD
(in KXW parlance), and have come up with a display format that looks reasonable, I think.
KXW labels complement-visibility clues as "Xjk", by the way.
Note that I don't display redundant clues (for word size N
I intend next to investigate the behaviour of pU
(probability of random grid having unique solution) for all Skyscraper modes (classic LS format, Kakuro format) with and without the extra clues.