It's worth pointing out that some implementations suffer from either duplicated content or one branch feels incomplete as it doesn't reference or link to another.

I appreciate this goes against the original ethos of keeping them separate. In my experience it also creates a new problem, where do you start?

What's the first thing to check out? Some readers will have a strong bias to one or another, and for simple topics it doesn't matter much. For some more involved projects it can be quite confusing.

In my experience, I'd suggest an overview and/or introduction page that makes this system and approach clear to users.

Good to read about your experiences and I greatly appreciate you sharing this with the wider world.