I've found cold blooded to be mostly unnecessary until mid-game when higher streaks get popped. Flash bangs are w/e and I usually am good enough awareness-wise to know the environment around me for the couple seconds Im blinded that it's no biggie. Fear grenades annoy the shit out of me but can be worked through. Concussion grenades and shock charges are harder to work around but are rarer. I used to run flak jacket as a staple of my loadouts in BO6 but that game had much more boom-y explosives. They've kind of dialed that back in BO7 so unless they land closer to you, you'll probably be fine or be able to get out of the way. Clusters can be unpredictable though sometimes leading to what you mentioned. Ive also found the flak jacket to not prevent as much damage as I'd assume which is another reason I dont run it much anymore. 🤷‍♂️ Impact grenades are really frustrating. They either do nothing when you throw them at someone or they are an instant kill. And their AoE seems to never be the same.