Blink: on-chain exit from Spark needs a wallet snapshot, not just the seed phrase; 3.0.46 saves it automatically
Blink says that if the Spark operators vanish, the 12-word seed phrase alone cannot recover your bitcoin on-chain. You also need a snapshot of the wallet state made while the operators were online. Starting with release 3.0.46, the app keeps such a snapshot: it is created after your first transaction, refreshed after every payment, and saved together with your cloud backup. In July the vendor ran a unilateral exit itself on mainnet with a real wallet and 100,000 sats, using open-source tooling, and documented every failure. The vendor's posts have the full write-up.
If you hold bitcoin in a Blink Spark balance, update to release 3.0.46, make a payment or transaction so the snapshot is created, and confirm that cloud backup is enabled and the snapshot date is recent. Re-check it after each top-up. Do not rely on the 12 words alone to recover these funds on-chain. If there is no snapshot and you cannot update, avoid adding to your Spark balance. If 3.0.46 is already installed and the snapshot is being refreshed, no further action is needed.