Quote from: Zaguru12 on Today at 04:12:19 PM

You’re definitely right the transaction that was RBF opt in will certainly be replaced but as for the transaction the transaction which was done through nodes full RBF you’re actually not replacing them but actually double spending them and nodes will have both the old and the new transactions since the nodes settings allows that.

Nodes can have both transactions in their mempool, but I don't think there's any node with such behavior. Nodes don't keep to conflicting transactions in their mempool.

If a node has enabled full RBF treats all transactions as RBF-enabled and would remove the first transaction from its mempool once it receives the replacement transaction even if it hasn't been flagged as RBF. (This is assuming the fee rate used for the replacement transaction is sufficient.

If a node has not enabled full RBF and the original transaction has not been flagged as RBF, it would reject the second transaction.

Note that it's possible that some nodes have the first transaction in their mempool and some have the second transaction in their mempool, but no node would keep both transactions.