In the StateChangelogReader, the restore consumer is currently hard coded to poll for 10ms at most per call.
It'd be nice to be able to configure the restore consumer to poll for a larger timeout (e.g. 500ms) to give it more time to accumulate records for the restoration task. In the main event loop for polling in StreamThread.java, the main consumer uses the POLL_MS_CONFIG set in StreamsConfig.java to configure the max poll timeout. We could construct a similar config in the StreamsConfig class, but prefixed with the processing type (restore in this case). Let me know if this sounds reasonable, and I'll create a KIP and PR.