if you were doing something more serious couldn't you mod it a bit to lock it in place? something along the lines of hose clamps that go around the stand and trellis? it wouldn't need to hold it up, just keep it from sliding off right?
If I understand ducducgooseme correctly, I would agree the stand wouldn't be good for getting the torque settings right. Not rigid enough. Seems like you could rotate the bike just enough to throw off the torque. Not really an issue of the bike staying on the stand.
