Can't you just dump the private key from the QT wallet?
Too many public keys... each requires the dumpprivkey entry.
Would rather script it using this tool across my many wallet.dat files.
You can dump all priv keys from a wallet.dat using
dumpwallet "filename"
Dumps all wallet keys in a human-readable format.
Arguments:
1. "filename" (string, required) The filename
Examples:
> bitcoin-cli dumpwallet "test"
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "dumpwallet", "params": ["test"] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/