I still don't get how there's any way holding it instead of selling it reduces taxes.
If you sell on vest, you pay income tax and 0 capital gains. If you sell after vest, you pay the same amount of income tax, and possibly nonzero capital gains.
If you sell on vest, you pay income tax and 0 capital gains. If you sell after vest, you pay the same amount of income tax, and possibly nonzero capital gains.
At least, that's my understanding. I'm not a tax accountant, though. This is not financial advice.