Batch exchange withdrawal to lightning requires covenants

Yes, participants can double-spend the batch using a commit transaction that spends from the previous funding output. However, this should not be done for the splice transaction as it cannot be used for 0-conf. Participants must be aware of the possibility of double-spends and should watch for them while waiting for confirmations. It is recommended to use a reasonable feerate and nVersion=2 for this standard transaction.