Dr. Frank Funkelstein wrote:
It is an additional exploration activity, your DM should handle it for you, similar to searching to detect traps.
It is a very situative feat. Wish i had it in Malevolence...
My GM says that it gives no bonus to perceiving the incorporeal so they would have to be noticed first and that it is an extra activity as you said.
I just don’t see the point of it if it is not for detecting/perceiving.