Where do I set the community base URL?

This matches my experience exactly. The hard part is staying consistent once the initial novelty wears off.

Great point. I had not considered the angle you raised in the second paragraph — it reframes the whole thing for me.

Tried this on a staging copy first and it behaved exactly as described. Confident enough to roll it to production now.

This is the answer I wish I had found six months ago. Would have saved me a weekend of trial and error.

Could you say more about how you measured the result? I want to try this but I am not sure what success would look like.