Source: Reddit

One thing that I've been trying to change for a month now is the achievement-thingy that pops up when you get the item. I have succeded to take away the screenshot-feature, but unfurtunately not with the achievement-like banner.

I'm not sure if this is already possible, hence the "needs confirmation" tag. It should be simple enough to add an option for it if need be.

I believe the options referring to "Announcements" only allow disabling of the attempts notification. It's handled by LibSink (via GetSinkAce3OptionsDataTable()), apparently, but I haven't found a way to disable the achievement toast separately.

Therefore, I suggest adding a toggle under the Announcements tab in the options. It could then disable the toast independently of any other announcement settings.