Yeah, I have the same need. I can explain my use case, as it’s very simple:
I’ve started a Discourse forum for a small Norwegian football 
team.
One of the categories is for match threads, where I post a subject for every match. When I do this, the current functionality, of having a template for use with new subjects, is very helpful for creating these match threads. 
But I want users replies to the match thread subjects to be pre-filled with something like:
Delete this sentence + the things below that don’t apply, so people can see when you wrote.
Before the match
4 min
After the match
And I don’t see a way to do that now, and not with the discourse-reply-template-component either.