Edit: Added a specific Use Case for clarity
Like most users I use parameters for my KWTs. Some parameters have a limited option pool e.g. paramater "WantACookie" can have 3 and only 3 values ...
You could probably get the same behavior using a table variable and doing lookups on it. Not the best way, but would do as a workaround.
It would be much easier to write things like this in a code unit instead of a KWT though.