Before I open an issue for it, I tried out

BracesOnWhenStatements

with the following config:

BracesOnWhenStatements:
    active: true
    singleLine: 'necessary'
    multiLine: 'necessary'

If I have a

when

with a clause that does no handling, I typically use

{}

because I like how it looks vs

Unit

(depending on the use case), but

BracesOnWhenStatements

reports that as a violation. Is that working as intended, or should the case of a clause with no handling be an exception?

You can open an issue to talk about those two cases. They sound reasonable.