Disable fee when basket value zero

We have a ticket product that is free but needs ‘purchasing’ to assign ‘stock’.
Normally WooCommerce would hide the payment options for a zero basket but with ‘Payment Gateway Based Fees and Discounts for WooCommerce’ enabled it shows the payment options and only allows checkout via the method with the surcharge – they pay the surcharge for a free ticket!
Can the surcharge be disabled if the basket value is below a certain amount?
Thank you

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