The "plastic" version ("ProShade 6093" and "ProShade 6093T", cat.no. 40738 and 40739) are pretty good, but may indeed break in several places.
The previous metal versions however are not without their faults either.
I had to bent a couple of them back into shape on a few occassions. But still: better bent than broken.
Yet i like the latest version best, since it will work on all lenses (with the right adapter), and doubles as filter holder (though no good for grads).
Of the two 6093 versions, the 6093 T has the better bellows. The one in the 6093 (without T) is rather stiff, and tends to pull or push, depending on whether it is kept extended or not, with enough force to make the bellows creep, and/or skew the thing.
The 6093 T also has a better brake, preventing bellows creep.
The previous version ("Professional lens shade 50-70", cat.no. 40676), the one with the foldable rail, is fine too.
It cannot be used with lenses having a mount larger than bayonet 70. And it will only take 75 mm gel filters in a slot in the adapter ring.
The oldest version ("Professional lens shade", cat.no. 40231) is much the same, but without the foldable rail.
One thing is that you will need the appropriate adapter rings, no matter what type you go for.
The earlier two use the same adapter rings. The ones for the 6093/6093 T are different.
You are using lenses with series 63 filter mount, and an adapter for these lenses ("Lens mounting ring 63") is only available for the two earlier types.
Don't expect much from any of these shades when used on the Biogon.
You might as well not bother with a bellows shade when using the SWC, and use the short fixed shade instead.