Hello, I recently went on an empty server with a guy who wanted to know how flashbangs exactly work because he kept getting killed by people that he flashed and that shouldn't be expected to be able to shoot back with any sort of precision or awareness.
To test this out we simply flashed each other and came to the conclusion that flashbangs dont reliably flash people hard enough for them to have any use in the game at all. Aside from the duration, which is a bit too low given the pace of the game (just my opinion though), the fact that you retain an amount of awareness allows you to have great chances to kill an attacker, even while fully flashed. Imagine yourself with an automatic weapon aiming at a door and getting flashed. You are able to make relatively good sense of your surroundings even when getting a flashbang right in front of your face. This is just one of many things that tip the scale in favor of the defender in this game, even when taking the necessary precautions. Here's a video showcasing this. As you can see I can still see him moving while I'm flashed.
The conclusion:
I hope that flashbangs can see a substantial buff, not only to range and possibly duration (if you guys feel thats appropriate), but also making you unable to see anything at all. Might sound harsh, but that's the whole point of those things, and I truly think it would be balanced, given that only the Advisor and Breacher can use them. You thereby would even be adding to the class system, giving these classes an advantage when breaching rooms, which is literally supposed to be the point of one of them. Right now the breacher is just a dude with a bomb and SMGs. He actually can't breach anything better than other classes.
Anyhow, I hope you can give some consideration to this and have a good day.