MRExecutor#pollInterval is currently hard coded to 50..1_000 for local mode and 500..10_000 otherwise. While being a sensible trade-off, one might want to poll more aggressively. For example, 1 seconds is usually too high for small integration tests.
A few experiments on internal test suites showed that lowering poll interval could halve execution time.
What do you think about adding a new configuration parameter that would override default config? I can craft a patch if needed.