> Put your damned messages where my attention has already been directed to BY YOUR UI.
Ok, so where does the toast go if you've already scrolled or otherwise navigated to a different area of the UI? These optimistic updated could take multiple seconds to succeed, and maybe as much as 30 seconds to fail.
If the "toast" can persist through that behavior, so can feedback positioned more sensibly. How does putting something on the other side of the (potentially huge) screen solve that "better?"
Not to mention that, if the operation fails, isn't it likely that the user will want to re-try? And that'll require access to the original control in all likelihood.
If the user scrolls away and the information is important, use a modal alert.
If you can't show me a spinner or other indicator that this is an ongoing operation (which I find preferable), and you think I will have moved away from the controls for this, then put it in a central location that I will see even if I am still on your control, not in a little box on the other side of the screen.
These toast notifications just are a bad solution. I often miss them, because I'm, you know, doing work, not scanning my monitors for notifications I mostly don't care about. (Redundancy is not harmless. Redundancy also trains me that your messaging is mostly noise.)
Ok, so where does the toast go if you've already scrolled or otherwise navigated to a different area of the UI? These optimistic updated could take multiple seconds to succeed, and maybe as much as 30 seconds to fail.