We had a similar thing going, people could set up a packages znc bouncer but the general rule was to assume everything was pretty much ephemeral to anyone not there. the best part to me about irc rooms is that they are allowed to be considered ephemeral, just like hallway talk and coffee breaks.
If something comes of the discussion. Update docs, post the chat log in the wiki, send an email with cliff notes and ask if others care to discuss, halt and get the right people in the room.
When you decide, 'hey, we have an idea, or a change in direction' you'd then document or make the case in a way that is more clear and user friendly than a mile of ephemeral chat. This is the same reason people send out meeting summaries instead of transcripts.
We've moved to this point where nothing is ephemeral. But a random chat isn't a good way to understand why things are being done. It's just too much to parse. And at some point new people are looking for a needle in a haystack and they just kinda checkout.
I thing documentation should be intentional, the why should be clear in a doc that doesn't waste time and is formated in a way that we have come to understand as the best practices of technical documentation. You'd start with a quick overview of both the problem and proposed or adopted solution and the reader can decide if they need more info.
Especially with remote work, I think it's important to have ephemeral areas for discussion without expectations that everyone keeps up on the whole chat. Thinking every team member needs to know every word of discussion is ludicrous.