[Tech Request]: [OPT] Plan diff

### Is there an existing issue for the same tech request?

- [X] I have checked the existing issues.

### Does this tech request not affect user experience?

- [X] This tech request doesn't affect user experience.

### What would you like to be added ?

```Markdown
After a new optimization algorithm, improvement etc, we need to make sure that new plan is indeed different and better. We should have a plan diff tool/function to check/verify this.

When upgrade etc, we also need to be sure important workload will not have plan regression.
```

### Why is this needed ?

_No response_

### Additional information

_No response_