This is an Advanced User Feature
Once selected it will enable "Unlimited Approvals" of transactions.
This action cannot be undone without advanced knowledge of blockchain interactions, by specifically reducing the approved amount.
Activating this feature will give the applicable smart contract virtually unlimited approval of token interactions. Checking this box will result in the next approval transaction performed to be for a virtually unlimited amount. This is advantageous for advanced users as it will not require future interactions with that smart contract to be preceded by an approval transaction.
This may reduce costs and time requirements for advanced users.