Ah.... So no red Numbers, how about interception or event stage?
]
Red numbers aren't too bad, as long as it's fairly close (maybe 10-15%?). Without mods, I can clear areas up to around 20% above my CP fairly easily most of the time, but that's with some relatively strong Nikkes on my team. Just don't go clearing an area with 30k expected CP using a team of 15k or something like that.
As for interception, that's one place I would not touch the mods - in fact, I'd avoid using them anywhere in the Ark area (pvp, interception, towers, sim room, lost sector). Events are probably fine-ish, so long as you build a team that makes sense (at least one each of burst 1, 2, and 3, preferably a 1-2-2 or 2-1-2 setup) and your Nikkes are leveled and geared.
The way I see it, the best use of the mod is to beat a stage where you are falling a little short of winning (boss has <20% HP left when time runs out, or you keep dying while it's at 5% etc, things like that), especially if there's a reward for that particular level.
It's good for a little nudge upward in damage/power, but making it obvious might just draw unwanted attention.