So? Just budget the proceeds. If you need a bit of extra help not spending it all at once it's not that hard to set up an automatic transfer on a monthly interval with a bank. Just set it up for {Proceeds} / 3 for three transfers.

That's only a Google thing. At Microsoft, for example, you can sell all the time.

There's no trading windows for insiders?

not if you enroll in auto-sell. mine vest and sell monthly.