When I found myself in a similar situation, I couldn't find a simple solution. Ultimately, switching to a more secure communication channel instead of a direct transfer helped, and the fees dropped significantly. This might not be ideal for larger amounts, but for smaller transfers, the difference was simply enormous.

Three months ago, the average gas cost on the mainnet was around 8 GWEI, but now it's skyrocketing to 40 GWEI without warning. Anyone transferring assets from Optimism to the Ethereum mainnet should calculate the fee before confirmation, not after. For example, I suggest you consider the Optimism Bridge ​https://defiway.com/bridges/bridge-eth-optimism-ethereum​​​ Transferring during off-peak hours, typically early weekday mornings, allows you to reduce costs more reliably than using any single tool.