I think this ability need a slight rework - so at least radaring new coming into range enemies would continue to work during entire duration of sonar.
Currently you press it - get all catched up in sonar radius enemies being marked on minimap and being covered with new crit point. But in many cases base duration of sonar is either way too much - enemies even at high level usualy die way faster, than sonar duration ends. It feels insonsistent.
So it would be a good idea either to reduce base duration AND base cost, so Sonar would be constantly casting ability, or add something for it