In that test, the clothing disappeared instantly. I've since tried a few other tests, and in one of them I saw the dress fly up out of the picture, so I wonder if possibly in the first test it did move, but instantly and entirely out of the viewport? I also tried a test very close to the T pose, and the dress stayed on and it worked (but of course there was nothing significant to drape it on in the T pose.)

I will have to experiment more with the animation dynamic test suggested above. I'm unclear exactly what I'm doing though. Note that I don't actually use animation at all, I just render still images. I'm assuming you wanted me to create 18 additional poses between the T pose and the final pose as if I had done animation, but I'm not sure why, since frame 20 would be the only one I would want to use and would stop the simulation on, can you explain?

Several additional questions surfaced during these tests.
One, I noticed that when I tried a T pose scene with no frames, upong pressing the Collision button the second time VWD started displaying an animated V3 in the Scene viewer from an earlier test (there is no animation in my current scene) and does not have my current figure's pose, Do I need to somehow clear VWD temporary files from somewhere between each use? Exiting and restarting the plugin, or DS, doesn't seem to clear it.

Another question, possibly related to the above question: I tried rotating my figure about 45 degrees forward (with attached clothing) to see if I could get more pronounced draping during one test while still keeping the T pose. I noticed that in the VWD scene viewer, the clothing had rotated, but the figure hadn't. Do I need to somehow fasten the clothing to the figure within VWD (in addition to the clothing being fit to the figure in DAZ Studio)?