This is essentially how it worked at Amazon/AWS. When raise season came around you would get less of a raise because stocks increased. I told my boss I was dissatisfied with my paltry 2%, and he told me there was nothing he could do because my projected stock grants had increased so much from when I had started that he couldn’t give me any more.

Where I've worked they do. Finance has a target in mind, and they take into account your vesting coming up in the year and pay you less based on how much they think those vestings are going to give you.

So if your salary is 100k, and they want to pay you 200k, and they see you've got 35 RSU vesting during the year and they predict that will net you 80k, then they'll top it off with an additional 20k worth of RSUs.

Basically the stock increase is accounted for. Those 20k worth of RSUs will vest say next year, and if next year they're now worth 60k, they'll just give you less RSUs again, because now they'll repeat the same math, and see you're probably going to make 160k.

You get the grant in the contract. New grants are adjusted based on share price.