How can I ensure that multicore platform components delivered at different time points exhibit the same behavior?

This is not inherently a multicore problem. Most avionics developers have mechanisms in place for the acceptance of new deliveries from suppliers, but these may not cover testing of multicore-specific problems. This is where tools that allow for efficient re-testing and automation are important. Once the on-target platform characterization tests for interference channel characterization and hardware event monitor validation have been implemented, they can be reused to ensure that results are consistent across different batches of platforms.