Tag Grenade - It doesn't have to be useless - Embark, boost the range to 20-30m!
As more scenarios are added that affect visibility (Night Raid, and Hurricane), there opens up a space for Tag Grenades to be super useful. But 6m is next to nothing.
If the range was opened up to 20-30m, tag grenades could become essential parts of a raiding kit to avoid unwanted conflict, counter rats, avoid traps, or get the jump on people. Not to mention avoiding hidden Arc (SHREDDERS) that might be at the end of a zipline, for example.
And while we're at it... how about tag grenade traps?