Appreciate the clear steps. The dry-run tip in particular saved me from a mistake I would not have caught otherwise.

I respectfully disagree on one detail. In my setup the opposite held true, though I suspect it comes down to community size.

Appreciate the clear steps. The dry-run tip in particular saved me from a mistake I would not have caught otherwise.

Run wp jetonomy flush-rules (or visit Settings > Permalinks and save) after changing the base slug. The 404s are stale rewrite rules — regenerating them fixes it immediately.