I've never liked the fixed handles on those Grivel screws. Several years ago (2006?) I was climbing some water-ice in NZ (my profile pic) and my partner had some new Grivel screws. One or two placements off the belay, with a bit of up and down movement, the rope ran over, then looped itself around, the handle and pulled tight as he moved up. Obviously it came tight on him and freaked him out, but did not pull him off, luckily. Just had to do an awkward downclimb to free it up.

I also think, looking at one of your lower pics there, that the rope could get caught and do a similar run-down-the-blade movement in a fall, as it gets caught behind the fixed handle.

1. Is it because of patent / design issues that Grivel can't make a folding knob design like BD?
2. Is it OP, or Smiley, that still have a BD-like screw, but with a fixed knob?

Years ago in Chamonix I bought some cheap Russian titanium screws that had a fixed handle, quite revolutionary at the time, but I quickly realised the dangers. Of the two I had left, one went as a leaver-screw somewhere or other, the remaining one sits in the bottom of my junk gear box as a reminder of how things change.