A very tough Bellagio 5/10 regular routinely checks dark OTF and OTT when he is first to act, whether or not he was the PF aggressor. Doesn't do it OTR. I have tried to analyze the value in giving up your opportunity to be the agg in exchange for not giving away information.
I've never tried this myself and am Interested in thoughts on the pros and cons of the dark check, particularly from those who have used it.