But I believed you can construct some "tricks" to actually detects the cheat when it is activated (not detecting the string itself).
I'll give you an example.
To "detect" iseedeadpeople, simply create a unit Neutral Hostile at the corner of the map and make it impassable (can't be reached in any method) with blocked vision.
Normally, you can't even see the unit, but when you activated iseedeadpeople, that unit is visible to you, thus it "detects" you cheat by using iseedeadpeople (because iseedeadpeople just opens the vision of the whole map).
There are many workarounds you can create, just be creative.