I have seen many people offer ways to incentivize arrests, many of them are good, I feel that quite a few of them disrupt the formula of the game in a way that would mean everyone who arrests will have almost the same type of strategic advantage, no matter player skill. A simple, easy, and tactically variable way to rework arrests, would be disallowing each team from hearing their arrested teammates, and providing negative xp multipliers on deaths, and not on arrests.
To me, intruder has always been about two things: communication, and turning tables. These changes would easily make