I’ve known people at IC level sell outside of windows and barely get a mention. Some people have odd vesting schedules for things like RSU’s, so sometimes it’s unavoidable.
At higher levels, it’s locked down considerably. My old director said that he had to have a meeting to go through a sale of his stock, so that it could be approved to be out of a window of potential releases in the company outside of his own division. I imagine that at VP+ level you need accountants just to handle what is a few clicks for an average corp worker.