There is a mempool fee market but when withdrawing from an exchange fees depend on the exchange you are using. Just use lightning to receive on Strike and then withdraw on chain for free with their 24h batch service. (Make sure your utxo is a least > 1M sats)
Discussion
TIL that LN withdrawals are a thing. Thanks! I’m working with them to figure out how to do it. (Only 1 of 2 is supported, so I’ll need to do an on-chain withdrawal for the other one.)