There is a need for this, for sure. The one thing to keep in mind here is that mods are designed to break a game and make it your bitch to run in ways it was not designed to run. Keep in mind that coding mods for this game is not an easy task. If it were, We would have more mods on here than forum posts.
With callouts, police radio, and other mods that are designed to increase immersion, available tasks to perform etc; the coding is simply using whats in the game and writing scripts to call up certain objects, animations, etc and run a certain way, much like rockstar does in creating the SP missions.
When you are doing something like freezing units you are in place when normally they are hard coded in the game to drive off after so many seconds, Coding a mod to freeze them is literally trying to stop the game from doing what is normal. This causes possible crashes and even the game to simply ignore it and do what it wants any ways...
That being said, I have been here about 6 months, and in that short time I have seen mods improve, and new ones created and alot of them. The experience does improve over time and it gets leaner meaner and runs better because these guys all work their asses of in their free time to try and create police role play utopia. The mods will not always work as intended, crashes will happen. One day what you want will be here. I know, Its happened for me and every other dude on here many times I'm sure.