Thanks @super_testnet for the response.

We always see the oracle as a judge of last resort, i.e. if two parties engage in a trade and open a DLC then they can always settle the DLC collaboratively. Only if the parties do not agree they take the oracle's signature and go on-chain to get their funds. The core idea behind these oracles is that they are not even aware that they are involved in a DLC. That being said, a DLC can always be settled without the oracle say-so.

What you are describing I would not call an oracle anymore as it is actively involved in the transaction creation. It is nevertheless an interesting idea, I'd consider a setup like this for my kids: i.e. if they want to spend more than X they have to at least get a second signature from their mum or dad 😅

The same solution can obviously also be used as a 2FA as you describe, i.e. you have one key on your phone and on on desktop and you need both devices to confirm tx over a specific amount.