How does this work if you're on a "manager schedule" and 50% or more of your job is supposed to be dealing with interruptions, having ad-hoc conversations, and the like?
I haven't read this book but in my experience, "shallow" work is also a necessity, always has been; it's just that in last decade or so we seem to have glorified it and let it replace all other forms of working.
IMHO it's not a matter of avoiding shallow work altogether, but more about blocking off time and space to really think and prioritize rather than react react react. As a manager I'd imagine you'd need less of this time than your direct reports but it'd be good to help protect their focus as much as you can, assuming they want it. (Depending on the nature of the work, some people seem to thrive on bite-size jobs.)
IMHO it's not a matter of avoiding shallow work altogether, but more about blocking off time and space to really think and prioritize rather than react react react. As a manager I'd imagine you'd need less of this time than your direct reports but it'd be good to help protect their focus as much as you can, assuming they want it. (Depending on the nature of the work, some people seem to thrive on bite-size jobs.)