To get a list of the pending transactions that my node is aware of I can easily call the eth_pendingTransactions jRPC call. This will give a big list of pending transactions, which all need parsing to find the pending transactions I care about by the client.
Is it possible pre-filter the transactions? Would eth_newpendingtransactionfilter be any help https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_newpendingtransactionfilter ? I can't seem to understand how this is related to pending transactions.