There’s a difference between “is capable of being misleading or false” and “usually cannot be trusted” - your suggestion is pushing investigation abilities into the latter category. Any positive could be a mind warp, fool frame, scorned frame or actually suspicious. Any negative could be brotherhood/dark wisp, drunk/invoker, tornado, prince jail, fool hide, merc guard or actually NS (which still could be NK).
You have no way of knowing any of these nor do you have any way of verifying any of these.After all, you think you checked 3 different people but actually two drunks deb’d you and then you checked one of them again. And this is assuming you keep the message that something occupied you - if you don’t then whoops a bulter occ’d you 3 times in a row and you think you checked 3 different people! And having to ask every morning “Hey did anyone redirect/occupy me” is tedious as heck.
Actually this problem extends to Princess too (though not as badly). Observer is fine though unless you change the message to be “x visited your target. Your target visited x” rather than the explicit numbering it has now.
That being said, actual suggestion in this thread is informing you of when your target was changed which makes it not quite as bad.