On usage of ApeCoin in ApeChain:
Because L2s derive their security from L1 Ethereum, and fees on L1 are paid in ETH, it is fundamental that any L2 ApeChain will have some requirement to spend ETH. If fees are paid in ApeCoin, this will fundamentally create sell pressure on ApeCoin to cover the L1 costs. This is not specific to the OP Stack, and is why the above cost measures are being minimized by the OP Stack are so important.
Also, all major ecosystem building blocks like NFT Marketplaces, Wallets, etc. accept ETH as a gas token already. Using ApeCoin as the gas tokens means having to work with all these ecosystem teams to adopt ApeCoin.
On the flipside, the introduction of sequencer revenue also introduces a new stream of funds which could be used by the ApeCoin ecosystem. For example, Zora uses the fees from its OP Chain as a rewards program for creators and collectors, which has been quickly gaining traction since being introduced earlier this year.
