Disable Mastery Pop-Ups?

[notstephcooper.9852]

So I probably will never unlock the Skyscale (using the borrowed one for the brief story step really irritated me & unless some mastery drastically changes the mechanics of the mount, I’m gonna pass) but every time I walk near one of those new rifts I get a pop-up talking about “unlocking the mastery on your new Skyscale”

Is it possible to disable them? Am I missing some toggle in the UI options?

Ty in advance!