I'd say keep it unplugged until you can test for actual oil pressure.

When you can hook a real gauge to it, you can test to see if that device is causing the oil pressure to actually be low, or if it is leaving the actual oil pressure alone and only changing what is displayed.

How can this thing make the oil pump to pump less? That makes zero sense. Drive it.

I'm not sure. I don't think it has an electronic oil pressure regulator. If the oil pressure is that much different based on whether that AFM delete thing is installed, I'd stay away from it. If it is actively dropping the oil pressure that much, I wouldn't want deal with whatever else it is doing behind the scenes.

I wonder if they've found a clever way to drop the oil pressure such that it is too low for the AFM lifters to collapse or something.

Put a gauge on it. This will not lower oil pressure. It may read lower but it is impossible to lower it.