I could not find any settings relating to it, and no extension adding ability to tweak it, so a built in ability to tweak the pop-up window's opacity will be much appreciated.

if you ask "what is the point?": the pop up sometimes get's in the way of adjacent code which i need to see even when a popup is being displayed, this adjacent code might be above, below or in the same line in which i'm writing so adjusting the pop-up's position or delay will not suffice.

thank you!