Could the Miner Use a Futures Contract Instead, and What Would Be the Trade-Off?

Yes, the miner could use a futures contract to hedge, which involves selling the futures contract (short hedge). The trade-off is the loss of customization.

Futures contracts have standardized sizes and expiration dates, which may not perfectly match the miner's production schedule. Furthermore, the miner would be subject to daily MTM and margin calls, introducing cash flow volatility.

The benefit is reduced counterparty risk and higher liquidity.

How Does MTM Reduce the Potential for a Massive Loss on the Expiration Date?
Why Is MTM Less Common in Traditional Forward Contracts?
Is the Cash Flow Impact of MTM the Same for Both Long and Short Positions?
How Do Exchanges Use MTM Data to Calculate Margin Requirements?
How Does the Concept of “Mark-to-Market” Affect the Margin Balance Daily?
What Is the Primary Difference in Margin Calls between a Traditional Futures Contract and a Perpetual Swap?
Does MTM Apply to Options Contracts in the Same Way as Futures?
How Does the Daily Mark-to-Market Process Work for Futures Contracts?

Glossar