I haven't made a post here before so here goes nothing...
The concussion grenade is a staple of Scout’s kit in both TFC and PF2, and one of the most fun items to use in those games. While it may seem like a spam tool to throw into chokes at first, its real potential comes from “conc jumping” where cooking the grenade and jumping at the last second launches you through the air. The tradeoff is temporary concussion, forcing you to adapt to a distorted crosshair and view. Scout is already the strongest mobility class, but it could be interesting to be able to swap his damage-focused secondaries for one that emphasizes movement and primary weapon skill instead.