It really shouldn't _need_ to break anything, though mistakes can always be made in some initial pass.
I would think you might also like long option key normalization so that one doesn't have to remember when typing commands `--how-toSpell_OptKeys-exactly`. Entering commands is often more ad hoc and personal than writing code, to the extent they are even distinct. Also, if it matters, I'm happy to donate [parseopt3.nim](https://github.com/c-blake/cligen/blob/master/parseopt3.nim) to the cause. That adds a few more features beyond optional symbols like "\--"/`stopWords`, and `optionNormalize`. It should be API/backward compatible by default, but I really haven't tested it much outside being driven by [cligen](https://github.com/c-blake/cligen) macros. E.g., I'm not sure how it fares against quoting issues that arose recently.