I've been playing a lot of Sicario recently and have heard of people using the Concussion grenade over the Smoke bomb.
The Smoke bomb did recently get an update where you can decrease the timer through kills even when it is in use but i still find the timer of it's use very short while the cooldown being way to long even with kills. It does however have a great potential to help teammates as they would avoid bullets and gain dodge but that is very much tied to the player's ability to know where to throw a Smoke bomb and the teammates want to stay in it and not go somewhere else.
The Concussion grenade doesn't have cooldowns but a limited supply. The crew ai has a boost that gives you an extra throwable for every 35 kills which would both remove the limited supply and be faster since if you get 35 kills with the Smoke bomb you still would have a 25 second cooldown. If running Fully Loaded aced you have a 5% chance of getting back a throwable which is more useful for online when not playing with crew ai.
The Concussion grenade could be used more often but has a short effect that doesn't support your stats in any way like dodge but gives a time window to do task like the Smoke bomb would.
(For clarification, I run a dodge crit build with Sicario and mostly play with crew ai alone as i don't really like playing with other people online until i reach at least infamy 1. Which means I don't have any experience using either with people. This post is purely for my curiosity on what others think about it as I can't find any other discussion about it.)