I thought your comment was familiar [0]. Yes, it seems there's always a risk involved. Better to simply be a contractor and work your own hours, and if a client gets mad, you can easily say you were working for another client during those hours.
Some companies will say no but it seems plausible someone could find a way to transition someone to a contract type situation if they really are valuable.
[0] https://news.ycombinator.com/item?id=29633539