How about adding an icon for every buff you currently have active somewhere on your screen? Different colors for each buff with a slightly flashing effect right before it’s about to fade.
This suggestion goes for both new and old buffs.
Few examples below to help you get an idea of what i mean.
Mudded up timer and when you can mud up again.
In range of the Support class buff that reduces damage taken by teammates.
Reckless damage boost timer.
Fanatic bonus damage and speed timer.
Yeah you get it. Simple indicators that start flashing when buffs are about to go off.