The question is how to turn it into a technical implementation.
We assume the situation is at least two people discussing and a moderator stepping in. Now the mod needs a button which makes the two write a shared conclusion. Lemmy could provide the means to write a “joint comment”, where both can edit and both need to sign it off. How to incentivize them though? The button probably needs to block the thread, post, or accounts until the joint comment is published.
Iterative development is how software development was done initially. Then there was a misunderstanding and Waterfall was invented. The DOD spread the idea that you should be finished with the design before you start implementation. I think in practice barely anybody really did Waterfall because of common sense.
Maybe Agile can be understood as the correction (or over-correction in many cases). What the movement celebrates as huge innovation is mostly a regression toward the mean.