Of course it's possible but the usual workflow of those in customer facing positions tends to be interrupt-driven rather than polled like how developers tend to

Of course it's possible but the usual workflow of those in customer facing positions tends to be interrupt-driven rather than polled like how developers tend to prefer to work (and there is definitely plenty of study on context-switching productivity loss, stress, etc.). Additionally, the amount of time available for developers to work with customers must be balanced with duties like feature delivery among others. Working across n different customers with m different needs even if time boxed to n hours / week you'll be likely left with customers that feel frustrated and that developers are disengaged when they're just overworked like everyone else.