.timeout user length BAN REASON
Works just as well. And means that if the user is a BTTV user with “whispers completely hidden” they still see the ban reason inline in Twitch chat.
You are right about appeals but that can be solved with a profile button, or regular timed chat command.
imo the lowest common denominator that basically has 100% success of delivery is Twitch Chat itself. So makes sense to deliver as much as possible via that medium.
As @3ventic points out, 17 people running the command in the same moment means 17 whispers which means you may hit the whisper rate limit, send the response in the medium it was requested, ie “main chat” and you send one response and can apply sane command cooldowns and avoid chat rate limits. Sure make the command reply via whisper, but if 100 people whisper the bot thats 100 whispers you have to reply back to.
The whisper rate limit is way lower than chat.