What is "Buy Instant" in Copy Trading?

Buy Instant determines if you want to frontrun / backrun the target trader's buy transaction.

If you tick Buy Instant and set the Frontrun Gas Multiplier more than 1, then it will frontrun the target's transaction.

If you tick Buy Instant and set the Frontrun Gas Multiplier to 1, then it will backrun the target's transaction. Backrunning ensures that the transaction is in the same block as the target trader's purchase but confirmed just after his transaction.

If you untick Buy Instant, then it will use Normal Gas Multiplier to send your transaction and this will happen after the target trader's transaction is confirmed.