Either way the damage is done. What makes one think that the performance assessment have been craved in stone. It would be better to stay to prove otherwise to “clean up” your reputation.

To be honest, as a1 would means a Low last drawn pay and the next employer would know that there is something wrong with you as people often not leave in year 1 during promotion period.

It is better off staying till one make senior than leave to clean up and get that last drawn boost.