EVM: transactions pending forever in MetaMask

Currently, you cannot cancel nor speed up your transaction in the EVM rollup. So if you send multiple transactions at the same time with the same nonce, only the first one will be included and the other will be marked as "pending", it happens because the kernel ignores them. But if we were in a mempool situation, the transaction could be replaced with highers fees, a different nonce or even canceled. The current situation is not enough, in case of invalid nonce your MetaMask is blocked.