If someone wants to wear their own gear or requests tactical gear for missions away from town, as long as it doesn't stand out or can be covered (since this started, in theory, as a stealth mission), they aren't going to have a problem with people wearing it. ADI has some bulletproof vests and equipment you might expect for a standard police unit, but they don't have a lot of SWAT-type or military-grade tactical gear to hand out.

For missions around town, they are going discourage flashy things like Keith's armor, but he'll mostly get verbal reprimands and told that, if he MUST wear that, he needs to tell people he's a cosplayer/something similar.