Or maybe don’t worry about this case too much? I think for most people who use forums it’s pretty clear that hitting reply in a forum topic will lead to a reply being posted in the topic, to everyone who has access to that topic. For those who are surprised by this, they will learn as soon as they save their reply.
@sjmscott How many people have complained about this in your community? It has never come up in my community before and we’ve been using discourse for 5 years.