A more frequent digest could work as well I think. Although I still would rather get an immediate notification.
We use our forum for client requests and then one of the team will pick it up. Before it’s picked up it will be discussed. Not everyone in the team is interested in every request. So they don’t need to know about the replies. But if they are interested, they should respond quickly, don’t want to keep the client waiting.
I agree you should not reply to a topic before you see the replies, but like I said: for Meta the watch category option is completely useless now. Way too many mails.
One of the things I dislike about mailinglists is you either have a digest - which is slow - or you get every single mail. Nothing in the middle. If Discourse is taking over the mailinglist concept, wouldn’t it be nice to make it ready for the next ten years as well?