What senior person wants to do this?
For most senior people, a new job is leaving an existing cushy job. We're not going to do that for some nonsense like this.
I don't know how you'd get a good signal from a "work-sample test" in under a week or so, in which case you've basically weeded out most of the people you want to hire.
I've since used that method when I was a hiring manager, both for technical roles, and even a Manager of Compliance. Was extremely successful, both for us on the hiring side, as well as two very good hires.