It is incorrect to think that combat espers are the most busy during a confluence. Of course, that's often what a lot of the normal populace thinks - they're the flashy jobs, the ones who take out the cores and rush in to save the people the DRT can't. The ones risking their lives and fighting the monsters and whatnot. They're the ones that get a lot of the media attention, because who doesn't want to imagine themselves as the powerful superhero saving people? They're the ones people see.
The actual busiest class of esper, most times, but especially during a confluence, are sensors. It is not close. Information is power, or to be more precise it is efficiency of leveraged power, which is better than flat power in almost all cases. Correct dungeon information is how you know that a dungeon just needs a bunch of guys with guns to kill, or if it needs a specific counter to get anywhere, or if it's secretly holding five million traps in reserve the minute you so much as breathe near its core. Sensors can locate where in a dungeon every victim is, where the core is, and give accurate accounts of monster abilities and numbers in advance. A decent one can turn a several day long slog into a quick two hour blitz. They prevent casualties, of civilian and servicemen and espers, and wasted resources trying to search for a needle in a murderous haystack. The really good ones can work in many different dungeon environments, in 4D and underwater and through tar and living swarms and smoke, with an ever-changing layout.
Minseo's not quite as - whatever Ji-woo is - as her purple haired partner, but she definitely gets a great deal of personal satisfaction out of being really damn good at her job.