This article presents some very good points on how the user experiences workflow, and I have been taking significant note of this in my recent work.
I shall preface this story with the detail that I have a hundred-odd notifications a day I have to read and, for the majority of them, act in some way whether it be a reply or logging into a system.
Having started wearing an Android watch recently, I became more immersed in my notifications. However, due to a OEM implementation of notification permissions I ended up having to allow notifications on the home screen as well as the watch. Whilst this would normally only be a nuisance from a privacy standpoint, I found that it was causing additional disruption in my workflow. When I would look at my phone and see the first line of a message, which I was not used to seeing, I would then subconsciously either unlock the phone, or if it seemed relatively benign read it on my watch. However, after reading on my watch I found I ended up opening it on the phone anyway to either reply or read it in full. Since switching to AOSP and disabling lock screen details, while keeping the watch on, I started only looking at my watch and then answering on the phone when necessary. This subtle difference in going from phone-watch-phone to watch-phone was a significant shift in how I started processing my messages. When I was reading first on my phone, I was trying to determine with too much effort if the message was worth my time. When I got it on the watch first, it became easier to optimize my workflows.
Over the course of hundreds of emails this became a significant interruption.
Even the most subtle of notifications can be devastating to a proper flow when presented in larger numbers.