I've been asked 'do you accept WTS as FDS' (or whatever the question is) twice.
The first time was with two elders after I'd stoped going to meetings suddenly: I said somthing like 'to say no makes me an apostate per the WT', then disucssed the dictionary definition of apostacy and heracy and took about 10 minutes to say nothing more except that I wasn't sure (about what???). I got away with that. The nasty conservative elder was frustrated, the happy liberal seemed amused. When they phoned for a second appointment, I said they were always welcome at my place (one of them was) but I had nothing religious to discuss: they never tried again. I was 3rd gen and had been a 'well qualified' MS only a couple of months before.
The second time was a couple of years later and after I'd moved territory. Someone arranged for an elder-pioneer to come around with his wife. He asked the question, slipped into in conversation as one does, and I said I didn't believe in God. He said, 'oh, well that makes it hard to believe in the FDS etc' and he reamained friendly and everything was good. He tried the usual arguments for God which I rebutted politley.
That could have gone badly if he had DF on his mind: but he didn't seem to.