This is probably fine!! I'd say for the detection portion, the person has to be somewhat relatively close for him to passively be detected (and also depends on ooc wants/desires), but if they're somewhat further away, he'd have to actually focus on finding someone.

Let say once per person per day and only one person at a time, but once the hr is up, he can work on someone else! And if it's too much, he'll be wiped.