Hi

It might be a mistranslation tbh cuz Snuff is a genre (please don’t search it up for your own sake)

Also wondering cause the snuff definition I know has NOTHING to do with what he’s talking about

I’ve always understood it as a slang term for not being up to a suitable standard in whatever situational context it might be used in like horse guy understood Dan wasnt mentally fit for da dick once his synapses finally fired with the equivalency of a f☆cking bic lighter and he had a thought for the first time

Not up to snuff means meeting the required standard. So when Jaekyung told Dan he was not up to snuff he meant Dan was still recovering from his physical and mental health issues and not ready for anything mentally or physically straining.

The literal definition is freaky crazy, but Jaekyung used it as SLANG which just means get freaky, fuck.