I like the pick up notifications for materials. They are not too obtrusive & can provide useful info regarding your teammates position & status.
It would be reasonable to allow players that don’t like them to toggle them off, tho.
One thing that does feel odd to me is that we are notified when a teammate picks up mats, but why not when they pick up a book, other mission object or health & ammo boxes? Yes all of these show on the HUD, but a notification when they’re picked up would be AT LEAST as useful as for mats. Seems odd to have one and not the other, to me.