multi signature – Handling UTXOs in Partially Signed Bitcoin Transactions (PSBTs) and Potential Double-Spend Scenario

I’m working with Partially Signed Bitcoin Transactions (PSBTs) and have a question about the behavior of transactions when the same UTXOs are involved in multiple transactions. Suppose I have a transaction created as a PSBT that requires multiple signatures. I sign it first, and before the second signer completes their part, I attempt to spend the same UTXOs in a different transaction.

PSBT Completion: What happens if I broadcast a new transaction using the same UTXOs before the PSBT is fully signed and broadcast? Can the new transaction be confirmed before the PSBT, making the PSBT invalid?

Double-Spend Protection: How does the Bitcoin network handle this scenario? Is the first transaction that gets confirmed the only one recognized, thus invalidating the other?

Wallet Behavior: What role do wallets play in managing UTXOs to prevent potential double-spends in such scenarios? Do they typically prevent the creation of a second transaction that would use the same UTXOs already allocated in a partially signed PSBT?

Any insights on how the Bitcoin protocol and network handle these situations would be very helpful.