Okay. Let me simplify the question, if possible, since I've yet to get an answer.=)
Imagine you are readying your WSM, or kettle, to smoke 2 trimmed racks of pork spares. That is all you intend to smoke. You only have this single probe/dual action unit. You want to monitor your grate temp, absolutely. Do you stick the probe in one of the racks, not that you want the meat temp monitored, but simply need somewhere to stick the stupid probe?
This is somewhat irrelevant, but I'm wondering if the meat end of the probe might not pick up some screwy readings since the ribs are relatively thin, while the grate end of the probe would give normal readings. Or, maybe you would stick the probe through a ball of foil, whereby both ends of the probe would give you grate temps.