Whatever works, works for me.

I've found that the hotglue trick has worked wonders on both of my translucent knobs when they worked loose - and both only needed doing once. For those without a hot glue gun, I reckon that a dab of silicone glue would work too.

However, and this is quite a big however, both knobs needed this treatment after a couple of months. Now maybe this is due to the casting resin used, and perhaps this won't happen with this particular batch, but I believe that it will. This could be a pain for those of us who are less mechanically inclined.

Visually, I definitely prefer the solid shaft, And I also like the idea of including a spring so people have a choice. But you've got to do whatever you feel is right. Having a split shaft wouldn't kill my order.