Sharing PVC’s seems like an anti pattern. My suggestion would be to share storage by having network storage instead like a NAS and share that with the same user in all Deployments. Generally for each *arr you need a /data and a /config so the data should be same location in the shared network solution. Check out https://hotio.dev/ for ready solutions which you only need to supply with the storage basically. Default settings works for me.

Wouldn’t that be a pain to maintain?

It has a nice vibe, easy to get engaged and I don’t spend as much time on it as previously which is a win-win.