Can Polkadot be staked via Blockdaemon?

Yes, Polkadot/DOT can be staked via Blockdaemon. 

You can utilize staking services with Blockdaemon from any custodian (including Coinbase), hot wallet, or any self-custody solution (e.g. Ledger) as long as the platform supports the ability to send staking transactions.

You can view our full Polkadot Staking Guide here.