It will get included in the SALT amount on Sch A, thats all its good for.

It's also good for a larger state refund if more than the annual limit was paid by multiple employers.  

Right! I looked at last year's W-2, and it was done correctly in Box 14 as CASDI rather than as local tax with SDI "locality." It's good to know more about this for someone whose clientele is 99% Virginia.

I see it reported in both box 14 and 20, I always enter it in Box 20, so I don't have to scroll way down the page to Box 14