It’s possible to spend on chain using this wallet I think:

https://github.com/BenWestgate/Bails

Which is great. I’m going to try it out but looks like it might require more shares than I’d personally like to manage.

In nostr:npub1r8l06leee9kjlam0slmky7h8j9zme9ca32erypgqtyu6t2gnhshs3jx5dk podcast with Polestra it sounds like you can use a regular hardware signer, but I think the co-ordinating wallet is key. I won’t be trying this with a lot of funds but will eventually get round to it!