Following​‍​‌‍​‍‌​‍​‌‍​‍‌ from #272 - when we were extending eth_subscribe to support standard subscription types, we decided to leave newPendingTransactions as a proxy to reth's standard behavior (mempool transactions).

It might be worthwhile to have a flashblocks-specific version that returns the sequenced transactions from the flashblocks state instead of the mempool transactions. The semantics are different:

• Standard newPendingTransactions: mempool txs (unconfirmed, may be dropped)
• Flashblocks variant: sequenced txs (included in flashblocks, higher confidence)

Options:

1. New subscription type like pendingFlashblockTransactions
2. Override newPendingTransactions to use flashblocks state
3. Leave as-is

@danyalprout is this worth exploring or is the current behavior sufficient?