Once custom stat gains come out believe me you'll most likely to see absence of mind popping off on mages alongside with manaflow band.
I already splash Precision for that and Alacrity on Lux and Zyra because they spend the first half of the game auto attacking a lot.
Speaking of underrated: Alacrity on mages. It's actually ridiculous how much structure damage you get out of that 23% aspd from Alacrity/Precision when you're stacking AP and have a long auto range. The hidden macro power there is actually very high.
The tradeoff is isn't even that consequential in comparison to a tier-1 Precision rune (Coup, Cut Down, Last Stand). If you look at the rune recap in post-game, those runes are only adding ~200-500 damage in an entire game. Unless the calculations are not very accurate, the attack speed is going to be worth more in terms of laning, CS, and then structures later in the game.