This is pretty good advice. But if you are going to hide the slack desktop while you are working then you should let people know. Otherwise, people will expect a response real time and wonder why you are ignoring them. It's human nature.
It’s not as if I ignore it completely, I can check Desktop 1 for flashing notifications with a simple left hand only Alt-1, and be back on my working desktop in like a second. That quickly becomes as autonomic as Ctrl-l, n, e, Enter when I’m in a browser.